Back up or move all volumes on the basic GPT disk you want to convert into a Primary Boot Record disk.
If the pre-install check fails the partition type check, do the following:
Follow the steps in the Microsoft KB article on how to switch to an Primary Boot Record disk.
Follow these steps to disable UEFI Secure Boot:
- Restart the computer then enter the BIOS Setup.
- Using the right arrow key, navigate to the Security menu. Using the down arrow key, select Secure Boot and then press Enter.
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- Using the down arrow key, modify the setting to Disabled and then press Enter.
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Refer to the manufacturer for particular steps on how to disable UEFI Secure Boot.
Follow these steps to enable Legacy Boot:
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Using the right arrow key, navigate to the Startup menu then use the down arrow key to select UEFI/Legacy Boot then press Enter. Select Legacy Only then press Enter.
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You may be prompted that the machine will no longer be able to boot after switching to Legacy mode.
- Press F10 to accept the changes and use the left arrow key to select Yes. Press Enter to exit and save the changes.
- Proceed with reinstalling the operating system of the device.
Refer to the manufacturer for particular steps on how to switch to Legacy Boot.