Note: My host is a mac running VBox 7.0 on macOS 11.7.2 (Big Sur)
My Windows 10 Guest was setup with master boot record (MBR). Windows 11 requires the UEFI Boot environment, trusted platform module (TPM) and secure boot.
Upgrading from Windows 10 to Windows 11 was very tricky and certain steps must be followed. I wanted to share the steps I took in hopes it will help other users out, with all the information in this post instead of searching all over the forum & internet to complete the process.
Prep Work:
Goes without saying, but backing up your original VM or Cloning a copy from the VirtualBox menu to "test" with is a vital step to prevent data loss.
Download the latest version of VirtualBox 7 (VBox 6 won't run Windows 11 due to the above-mentioned Windows 11 requirements). As of this writing, Guest Additions 7.0.x are not working properly with Windows 11 guests (see other forum threads) You WILL NEED the Guest Additions 6.1.40 file downloaded: Referenceviewtopic.php?p=527364#p527364on how to downgrade your Guest Additions version from 7.0.x to 6.1.40. Thanks to H00die memberlist.php?mode=viewprofile&u=133977
Step 1: Know the administrator account password! You will need this later.
Step 2: You will need to convert the Windows 10 MBR to UEFI boot environment. If you already have your Windows 10 VM powered up, in the search bar type “Recovery” and select “Recovery Options”. Under Advanced startup Items, select “Restart Now”. (or press F11 on bootup to boot into Windows Recovery Environment (RE))
Step 3: You should now see the Windows Recovery Environment (RE). Select Troubleshoot, Advanced Options, Command Prompt. System will then prompt to select a user account with admin privileges, and enter the associated password.
Step 4: You will now enter the commands to convert the boot environment from MBR to UEFI. At the ..\windows\sytstem32\> command prompt, enter:
mbr2gpt /validate (If you see the “Validation completed successfully” message, proceed to the next step. If you see any errors, your disk or system may not meet the conversion requirements.)
mbr2gpt /validate /AllowFullOS
mbr2gpt /convert
After completion, you should see a list of about 14 commands and return to the command prompt. You can now type Exit and select the option to “Turn Off PC”.
Step 5: DON’T attempt to boot or restart your VM until the following changes are made in the VBox VM Settings:
System/Motherboard tab
a.) Check Enable EFI
b.) Check Enable Secure Boot.
c.) Under TPM, select 2.0
d.) Verify Base Memory allocation (Windows 11 must have at least 4GB RAM)
System/Processor tab:
Verify: Must have at least 2 processors for Windows 11
Storage:
Attach the VBoxGuestAdditions 6.1.40 ISO
Attach your Windows 11 install media ISO
Click OK
Step 6:
You can now boot your VM. If you see “Press any key to boot….” DON’T boot to the Windows 11 ISO image. Boot Windows 10.
Step 7: Once logged in to Windows 10, Run the Windows 11 installer "Setup" from your attached Windows 11 ISO (I skipped the option for check for updates).
Step 8: After the numerous steps of the installation process is complete, I re-installed the Guest Additions installer 6.1.40. Might not be required, but figured I would just in case to get all the proper VM drivers installed after the Windows 11 install.
Hope that helps! And hopefully, the VBox 7.0.x Guest Additions will get fixed at some point to allow you to run Windows 11 without it locking up.