> For the complete documentation index, see [llms.txt](https://docs.plenit.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.plenit.com/docs-en/support/tutorials/windows/how-to-convert-uefi-disks-to-bios.md).

# How to convert UEFI disks to BIOS on your Windows server - Plenit

Find out here **how to convert UEFI disks to BIOS** to avoid execution problems within the Plenit platform.

Machines deployed with technology **UEFI technology are not supported** by Plenit, specifically the virtual machines of **Azure Gen2** (Second Generation) and the \*\*Hyper-V Get2 \*\*virtual machines (Second Generation).

When trying to boot a machine of this type, we may possibly encounter an error like the following or very similar:

*iPXE: (hrrp\://ipxe.org) 00:04.0 CA00 PCI2.10 PMM-0010000100011020 CA00*

*Press F12 for boot menu.*

*Boot device: Hard Disk -- success.*

*Boot device: CD-Rom -- Failure: could not read boot disk*

*No bootable device.*

*Powering off in 30 seconds.*

**NOTE:** *Also, in Step 5 of this tutorial you can find a guided procedure to **solve boot corruption problems** on a Microsoft Windows server.*

 

### **How to convert UEFI disks to BIOS?**

#### **Prerequisites or pre-configuration**

To successfully complete this tutorial and **convert UEFI disks to BIOS** you will need:

* On the one hand, being \*\*registered on the Plenit Platform \*\*with an organization and being registered on it after doing [Log in](https://admin.jotelulu.com/){target="\_blank" rel="noopener"}.
* On the other hand, [having set up a Servers subscription](https://jotelulu.com/soporte/tutoriales/como-desplegar-servidor){target="\_blank" rel="noopener"}
* Have a\*\* Windows server migrated with boot problems \*\*within the subscription.
* Have a\*\* operational Ubuntu 20 server \*\*within the subscription.

\*\*NOTE: \*\**Before carrying out the procedure, it is recommended to back up the disk we are going to work on, so that it can be recovered in case we make any mistake during the process, since, among other things, it is possible that we make a mistake and delete its contents.*

**NOTE:** \*At the end of the procedure, it is advisable to delete the backups we have created and do not need to keep, since although there is no charge for the backups that may be made, there is a charge for the stored disk space.  \*

 

#### **Step 0. Prepare the Ubuntu machine**

If you do not have a **Ubuntu 20 machine** provisioned in the server subscription, \*\*it must be deployed \*\*so that it can be used to recover the disk that is causing problems.

Also, the virtual machine must be prepared to **be accessed** via a **direct SSH connection** so that it is more convenient than working from the console. For this, it will also be necessary to open the **SSH port in the firewall** of the Plenit server subscription and to use some connection program, such as PuTTY in the case of connecting from a Microsoft Windows computer.

 

#### **Step 1. Disk preparation**

The first thing to do is **stop the virtual machine** whose boot is not working correctly. To do this, you must access the subscription where the virtual machine that fails to boot is located and go to the specific server that is failing.

Once there, you must go to the top of the screen and **click "Stop"** (1) to **stop the machine** virtual.

![Paso 1. Paramos la máquina virtual que está dando problemas para poder
desconectar los
discos](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso201.20Paramos20la20mC3A1quina20virtual20que20estC3A120dando20problemas20para20poder20desconectar20los20discos-800x404-1.jpg){decoding="async"}

Step 1. We stop the virtual machine that is causing problems so we can disconnect the disks

Once you are sure that the machine has stopped, you **must go to the disks section** (2) of the server subscription, find the disk belonging to that virtual machine and **click on the three dots** (3) to\*\* select the "disconnect" option\*\* (4).

![Paso 1. Desconectamos el disco que queremos modificar para poder
operar con
el](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso201.20Desconectamos20el20disco20que20queremos20modificar20para20poder20operar20con20el-800x396-1.jpg){decoding="async"}

Step 1. We disconnect the disk we want to modify so we can work on it

At this point you already have **the disconnected disk** from the source server and **it must be connected to the Ubuntu server** 20 that will be used for the boot repair procedure by changing GPT to BIOS.

To connect this disk to the Ubuntu machine, you must\*\* go to the disks section\*\* (5) of the server subscription, which in principle is the section you are in right now, find the disk that has been disconnected from the virtual machine and **click on the three dots** (6) to\*\* select the "Connect" option\*\* (7).

![Paso 1. Conectamos el disco a la máquina Ubuntu para su
manipulación](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso201.20Conectamos20el20disco20a20la20mC3A1quina20Ubuntu20para20su20manipulaciC3B3n-800x353-1.jpg){decoding="async"}

Step 1. We connect the disk to the Ubuntu machine for handling

When selecting the disk, you are asked to **select the server** (8) to which it must be connected, so you must select the appropriate machine and **click "Continue"** (9).

![Paso 1. Seleccionamos el servidor al que se va a conectar el
disco](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso201.20Seleccionamos20el20servidor20al20que20se20va20a20conectar20el20disco-800x291-1.jpg){decoding="async"}

Step 1. We select the server to which the disk will be connected

Once the **disk is connected to the server**, you must **go to the servers section**,\*\* select the server\*\* and **boot the virtual machine** (10) to which we have just connected the disk to begin the actual procedure.

![Paso 1. Arrancamos el servidor sobre el que vamos a tratar el
disco](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso201.20Arrancamos20el20servidor20sobre20el20que20vamos20a20tratar20el20disco-800x302-1.jpg){decoding="async"}

Step 1. We boot the server on which we are going to work with the disk

After this, **we create an inbound rule in the firewall** of the server so we can **access remotely via SSH** and work more comfortably, instead of connecting from the integrated console in Plenit, since working from the console is a bit more inconvenient.

For this, you must \*\*go to the server subscription \*\*, you must **access the server settings** of Ubuntu and, at the bottom of the screen, in the "Firewall -- Inbound rules" section, you must **click "New rule"** (11).

![Paso 1. Creamos una nueva regla de entrada para conectar por SSH en el
firewall de
Plenit](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso201.20Creamos20una20nueva20regla20de20entrada20para20conectar20por20SSH20en20el20firewall20de20Jotelulu-800x387-1.jpg){decoding="async"}

Step 1. We create a new inbound rule to connect via SSH in the Plenit firewall

In the new window, the following **connection details**:

* **Select network**: (12) The **network through which the connection will be made must be selected**. It will generally be the one already configured.
* **IP or Network**: (13) **The IP or network from which the connection can be made**. By default it is set to "Any IP" but **it is recommended to limit it**, by entering the customer's company IP or IP range, since these connections will not be made from anywhere else, thus minimizing the attack surface.
* **Protocol and Public Port**: (14) This is the port we want to **use to connect**, it consists of Protocol (TCP or UDP); in this case **TCP** and the **port number**, which in this case is **port 22**.
* **Public IP**: (15) The public IP of the server to which it will connect through this rule.
* **Private (IP)**: (16) The private IP of the server to which it will connect through this rule.
* **Private Port**: (17) This is the port we want to **use to connect**, on the internal side, in this case only the **port number (Port 22) is needed**.

Once everything is configured, you will have to \*\*click "Continue" \*\*(18) so that the rule is created.

![Paso 1. Creamos una regla de conexión para SSH en el firewall del
servidor dando los
datos](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso201.20Creamos20una20regla20de20conexiC3B3n20para20SSH20en20el20firewall20del20servidor20dando20los20datos-800x564-1.jpg){decoding="async"}

Step 1. We create a connection rule for SSH in the server firewall by providing the data

After this configuration, you will be able to **connect to the GNU/Linux server console via SSH** using a connection program such as PuTTY, which is one of the most widely used programs for connecting via SSH (and other protocols) from Windows computers.

\*\*NOTE: \*\**You can download the PuTTY program from the following* [*URL*](https://putty.org/)*{target="\_blank" rel="noopener"}.*

![Paso 1. Usamos PuTTY para conectar al servidor sobre el que vamos a
hacer la
operativa](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso201.20Usamos20PuTTY20para20conectar20al20servidor20sobre20el20que20vamos20a20hacer20la20operativa-800x378-1.jpg){decoding="async"}

Step 1. We use PuTTY to connect to the server on which we are going to perform the procedure

 

#### **Step 2. Disk modification procedure**

The next thing to do is **connect via SSH** from the computer used for administration, using the tool you have chosen, such as the PuTTY suggested earlier.

Once connected, the first thing to do is to **list the available disks** on the server so that we can identify the disk we have mounted for repair. Several commands can be used for this, but in our case **the command "fdisk -l" must be used** (19) which shows all available disks and partitions on the computer.

When **show the existing disks** (20) which will generally have a similar form to:

/etc/xvda1\
/etc/xvda2\
/etc/xvda3\
/etc/xvdb1\
/etc/xvdb2\
/etc/xvdb3\
/etc/xvdb4\
/etc/xvdb5

In this case, we see that all **start with "/etc/"** this is because the **devices and partitions** have their configuration file linked to the mounted disk.

Also, we can see that after that, they all share a string, the one made up **of "xvdb"**.

Finally, you can see that there is **an "a" or a "b" followed by a number**. This is because each disk in the system has an assigned letter, ordered alphabetically, therefore starting with "a", followed by "b", etc. Also, **each partition of the disk receives a number** that starts at "1" and keeps increasing.

With what we have just discussed, the list of disks and partitions shown above, "/etc/xvda1", "/etc/xvda2" and "/etc/xvda3" will belong to the disk "/etc/xvda", while "/etc/xvdb1", "/etc/xvdb2", "/etc/xvdb3", "/etc/xvdb4" and "/etc/xvdb5" will belong to the disk "/etc/xvdb".\
That said, from the list shown to us, **we will be interested in disk "b"**, since the first one (a) is the one running the Ubuntu operating system and the second one (b) is the one mounted for repair, but beware, this will depend on whether we have more disks mounted on that server.

![Paso 2. Comprobamos los discos conectados en el servidor para
identificar el que se ha
pinchado](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso202.20Comprobamos20los20discos20conectados20en20el20servidor20para20identificar20el20que20se20ha20pinchado-800x436-1.jpg){decoding="async"}

Step 2. We check the connected disks on the server to identify the one that has been plugged in

The next thing to do is **edit the disk** that you want to change (commonly "/etc/xvdb") and for this you must **run the command** "gdisk /dev/xvdb" (21).

When running this command, it will return **information about the state of the partition table**, reporting its type. In the case at hand, it should be of type GPT so it **must show a "GPT: Present"** (22), which will indicate that it is a GPT-type disk that does not have any kind of problem.

**If a message like "GPT: Damaged" is shown** an **additional step described in step 3 must be performed**. If the case you are dealing with shows this error, go to Step 3 and come back here when you finish doing it.

![Paso 2. Editamos el disco con gdisk y comprobamos el estado de la
partición](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso202.20Editamos20el20disco20con20gdisk20y20comprobamos20el20estado20de20la20particiC3B3n-800x436-1.jpg){decoding="async"}

Step 2. We edit the disk with gdisk and check the partition status

In case **the message is "GPT: present"** the following options must be **entered** (23) from the "gdisk" menu in the order shown below:

**r**: Prepares the recovery and transformation options.

**g**: Converts the partition from GPT to MBR.

**s**: Prepares the MBR partition.

**p**: Shows the MBR table.

**w**: Writes the MBR partition table.

**and**: We will validate the write and exit the program.

![Paso 2. Comenzamos a lanzar los comandos de gdisk para hacer el cambio
en el
disco](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso202.20Comenzamos20a20lanzar20los20comandos20de20gdisk20para20hacer20el20cambio20en20el20disco-800x418-1.jpg){decoding="async"}

Step 2. We begin running the gdisk commands to make the change on the disk

With this, this part of the procedure will have been **completed** and you must **go to Step 4**.

 

#### **Step 3. Procedure in case you get the message "GPT: Damaged"**

**IMPORTANT:** *The following should only be carried out if the disk shows the message "GPT: Damaged".*

\*\*NOTE: \*\**Remember that it is a good practice to back up the disk we are working on before carrying out all this procedure.*

**When running the command "gdisk /dev/xvdb" the error "GPT: Damaged" has been shown** so additional work must be done.

This consists of when the **"gdisk" command returns the prompt** the following **options must be entered in the order** (24) listed here:

**p**: Print the partition table information.

**w**: Write the partition table and exit.

**and**: Confirm writing the partition table.

![Paso 3. Continuamos con los comandos de gdisk para recuperar la
partición
GPT](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso203.20Continuamos20con20los20comandos20de20gdisk20para20recuperar20la20particiC3B3n20GPT-800x418-1.jpg){decoding="async"}

Step 3. We continue with the gdisk commands to recover the GPT partition

To check that everything has gone well, you must\*\* run the command "gdisk /dev/xvdb" again\*\* (25) and verify that the message "GPT: present" is shown instead of the "GPT: damaged" that was shown previously.

![Paso 3. Comprobamos con gdisk que el estado de GPT es present y no
damaged](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso203.20Comprobamos20con20gdisk20que20el20estado20de20GPT20es20present20y20no20damaged-800x416-1.jpg){decoding="async"}

Step 3. We check with gdisk that the GPT status is present and not damaged

If everything has gone well, you can return to the point in Step 2 where we were before moving on to solve the GPT problem.

 

#### **Step 4. Windows boot repair**

At this step, the disk conversion has already been done, but **it is still not bootable within Windows**. For this reason, you must **power off the virtual machines**, **disconnect the disk from the Ubuntu machine** that was used to recover it and **connect it to the Windows machine** from which it had previously been disconnected.

**NOTE:** *The process of disconnecting a machine to connect it to another has been reproduced previously, so it will not be described again. If the reader has doubts, we refer them to the procedure previously carried out.*

The next thing to do after reconnecting the disk is to **insert an ISO image so that it can boot** from it, in the same way as if we were working with a physical machine and wanted to perform maintenance or recovery tasks.

To do this procedure, you must **go to the administration portal** of Plenit, **access the server subscription** where the server is located, **select the server** and, in the server administration or editing window, go to the top of the window, where initially \*\*"No ISO" \*\*(26) can be read and open the options to **select the ISO** (27) corresponding to the server's operating system (for example, Windows Server 2019).

![Paso 4. Seleccionamos la ISO a montar en el servidor para poder lanzar
las opciones de
recuperación](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso204.20Seleccionamos20la20ISO20a20montar20en20el20servidor20para20poder20lanzar20las20opciones20de20recuperaciC3B3n-800x390-1.jpg){decoding="async"}

Step 4. We select the ISO to mount on the server so that we can launch the recovery options

Once this is done, you must **boot the machine.** To do this, in the Plenit administration console you must\*\* click "Power On"\*\* (28), **confirming** when asked if you want to power on the server.

![Paso 4. Arrancamos la máquina
virtual](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso204.20Arrancamos20la20mC3A1quina20virtual-800x389-1.jpg){decoding="async"}

Step 4. We boot the virtual machine

After this, you must wait a moment while the machine boots and then you must **launch the console** (29).

\*\*NOTE: \*\**We will probably not manage to connect on the first try, since the system is booting, which is why you must launch it as many times as necessary until the boot from the ISO is shown.*

![Paso 4. Lanzamos la consola de administración remota disponible en la
plataforma](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso204.20Lanzamos20la20consola20de20administraciC3B3n20remota20disponible20en20la20plataforma-800x389-1.jpg){decoding="async"}

Step 4. We launch the remote administration console available on the platform

When you manage to open the console, you must **launch boot from CD/DVD**, that is, from the ISO that has been inserted, you must wait for the message *"Press any key to boot from CD or DVD..."* you must **press the "Enter" key** (30) so that it boots from the image and begins loading the system files.

![Paso 4. Pulsamos enter para que cargue la imagen que hemos conectado a
la
máquina](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso204.20Pulsamos20enter20para20que20cargue20la20imagen20que20hemos20conectado20a20la20mC3A1quina-800x452-1.jpg){decoding="async"}

Step 4. We press enter so that the image connected to the machine loads

**NOTE:** *It is quite common not to catch the key press on the first try, so you may end up seeing the operating system installed on the virtual machine boot. If this happens, you must restart or power off the machine and try again.*

At this point, if everything goes well, the system **will begin to load the ISO** and decompress the binaries so that it can run the console with which we must perform the procedure, so we will have to be patient while it loads.

![Paso 4. Esperamos mientras se carga la imagen del
sistema](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso204.20Esperamos20mientras20se20carga20la20imC3A1gen20del20sistema-800x450-1.jpg){decoding="async"}

Step 4. We wait while the system image loads

When the **"Windows Server Operating System Configuration" window**loads, you must **click "Next"** (31), and it does not matter too much whether it is in one language or another since we will work in command line.

![Paso 4. Hacemos clic en siguiente para pasar al siguiente
menú](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso204.20Hacemos20clic20en20siguiente20para20pasar20al20siguiente20menC3BA-800x451-1.jpg){decoding="async"}

Step 4. We click next to move to the next menu

In the next window, you must **click "Repair your computer"** (32) to enter the system recovery options.

![Paso 4. Hacemos clic en Reparar
equipo](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso204.20Hacemos20clic20en20Reparar20equipo-800x450-1.jpg){decoding="async"}

Step 4. We click Repair your computer

After this, a new window will appear in which you must **select "Troubleshoot"** (33).

![Paso 4. Seleccionamos solucionar problemas en el menú
visual](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso204.20Seleccionamos20solucionar20problemas20en20el20menC3BA20visual-800x451-1.jpg){decoding="async"}

Step 4. We select troubleshoot in the visual menu

And finally, within the advanced options you must **select the "Command Prompt" option** (34) which will launch a Windows CMD window that we can now work on.

![Paso 4. Seleccionamos símbolo del sistema entre las opciones que se
nos
ofrecen](https://jotelulu.com/wp-content/uploads/2022/10/5_Paso204.20Seleccionamos20simbolo20del20sistema20entre20las20opciones20que20se20nos20ofrecen-800x451-1.jpg){decoding="async"}

Step 4. We select Command Prompt among the options offered to us

Now that you have a **Windows command prompt console**, commonly called "Command" or "CMD", you must **run a series of commands** (35), which are the same ones used when making a bootable USB disk.

The commands to run are as follows:

*diskpart*

*list disk*

\*select disk \*

*list partition*

*list volume* (it will help us identify the volume where Windows is installed)

Where:

* "" will be the disk that you want to use to boot the system, and you cannot choose a data disk.

Once this is done, you must **review until you find the "C:" partition**, launching the following **commands and using the corresponding partition number** (36) for the partition found.

\*select partition \*

*active*

*exit*

After running the "activate" command, if everything goes well, you should receive the **message "Diskpart marks the current partition as active"** (37).

![Paso 4. Lanzamos diskpart y hacemos la operación sobre el
disco](https://jotelulu.com/wp-content/uploads/2022/10/2_Paso204.20Lanzamos20diskpart20y20hacemos20la20operaciC3B3n20sobre20el20disco.jpg){decoding="async"}

Step 4. We launch diskpart and perform the operation on the disk

Once this is done, the partition must **be made bootable**, so you must **find the letter** where the Windows operating system is, which is likely to be "D:" since "C:" is used by the recovery system, and on the other hand, you also need to find the drive letter where the ISO has been loaded, which would be the equivalent of the CD/DVD, and "E:" or "F:" are the most common options.

When you are clear about the drive letters, you must **run the following commands** (38):

*F:*

*dir*

*BCDBOOT D:\Windows*

*bootrec /fixmbr*

Where:

* F: is the drive where we have mapped the ISO (the CD/DVD) in our case.
* D: is the drive where the virtual machine's Windows operating system is located.

After running the "bootrec /fixmbr" command, if everything goes well, you should see the **message "the operation completed successfully"**.

If this is the case, the procedure will have been completed, so you can **restart the machine** and **check that the machine starts** without problems.

If, on the contrary, when running the command "BCDBOOT D:\Windows" it **returns the message "Error trying to copy boot files"**, it will mean that the command has failed, so you **should continue in Step 5**.

![Paso 4. Recuperamos el arranque de
Windows](https://jotelulu.com/wp-content/uploads/2022/10/1_Paso204.20Recuperamos20el20arranque20de20Windows-scaled-1.jpg){decoding="async"}

Step 4. We recover the Windows boot

 

#### **Step 5. Solution to the boot file copy failure**

**NOTE:** *This procedure should only be applied if the execution of the command "BCDBOOT D:\Windows" has failed and returned the error "Error trying to copy boot files".*

To solve this problem, you only need to\*\* follow the following procedure\*\* without skipping any step and in the order set out below.

First, you must **launch the "diskpart" application** (39) to locate the Windows operating system disk and partition:

*diskpart*

*list disk*

When it is clear **which disk must be selected** (40) to use it:

*select disk 0*

Next, you must **list the partitions** and **select the one that has Windows** installed and **mark it as active** (41):

*list partition*

*select partition 3*

*active*

*exit*

![Paso 5. Ejecutamos la primera parte de la recuperación del
arraque](https://jotelulu.com/wp-content/uploads/2022/10/1_Paso205.20Ejecutamos20la20primera20parte20de20la20recuperaciC3B3n20del20arraque-800x452-1.jpg){decoding="async"}

Step 5. We execute the first part of boot recovery

Finally, you must **launch the repair commands** (42) from the ISO drive (CD/DVD):

*dir*

*BCDBOOT D:\Windows*

*bootrec /fixmbr*

Where:

* F: is the drive where we have mapped the ISO (the CD/DVD) in our case.
* D: is the drive where the virtual machine's Windows operating system is located.

![Paso 5. Ejecutamos la segunda parte de la recuperación del
arraque](https://jotelulu.com/wp-content/uploads/2022/10/Paso205.20Ejecutamos20la20segunda20parte20de20la20recuperaciC3B3n20del20arraque.jpg){decoding="async"}

Step 5. We execute the second part of boot recovery

With this, the boot should already have been recovered.

 

### **Conclusions**

The process described in this tutorial, **such as converting UEFI disks to BIOS,** allows the conversion of a Windows UEFI machine coming from **Microsoft Azure** or a **Microsoft Hyper-V** to allow it to be run on the Plenit architecture.

Likewise, in this same tutorial, you can see how **to solve boot corruption** on a Microsoft Windows machine.

As you can see, these are somewhat more complicated processes than usual, but they have been described in a guided way through well-defined steps so that the reader has no problems.

We hope that with this small guide you will have no problems converting UEFI disks to BIOS and no problems solving possible issues in the boot sector, but if you do, do not hesitate to contact us so that we can lend you a hand.

**Thank you for your trust!**


---

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