How to Switch VM from BIOS to UEFI Boot, Help
I built a gold Win10 image in the VM but it failed when I tested the deployment. The BIOS should be set to use UEFI and secure Boot. I need to add a new VMDK and format it as GPT. Does anyone know an easier way to do this?
Best Answered by
Cici· Answered on Jul 06, 2025
BIOS and UEFI support different partition styles. If you want to boot from UEFI, the first task you have to do is to convert the partition format. BIOS works with MBR, while GPT uses UEFI for booting.
Further Reading: UEFI vs. BIOS: What's the Difference and Which is Better
There are many tools to convert MBR to GPT, but Windows built-in tools require you to delete the existing partition first. So why not try a safe and effective conversion tool? EaseUS Partition Master Server can convert MBR to GPT without losing any data. It is highly compatible with all Windows systems and hard drives. You can effortlessly and successfully convert MBR to GPT.
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The tool is simple and easy to use. Following are the specific steps for switching the VM from BIOS to UEFI boot:
Note: Please make a backup in advance to protect your important data.
Step 1. Download and open EaseUS Partition Master.
Step 2. Select "Convert MBR to GPT" in the Disk Convert section and click "Next."
Step 3. Select the target MBR disk and click "Convert."
After converting to a GPT disk, install the following steps to change the boot mode:
Step 1. Restart your computer and press and hold F2 to enter the BIOS environment.
Step 2. Find the boot sequence, change Legacy to UEFI, change SATA operation to RAID, enable Secure Boot, etc.
