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Go to SolutionAs mentioned above, converting MBR to GPT on a disk that contains an OS is NOT a simple "convert to GPT" operation. You have to create an EFI and MSR partition and update the bootloader. The MBR2GPT utility will do this as long as you're running Win10 1709, but I would recommend capturing an image backup just to be safe before you do this. If you run it from within live Windows rather than a bootable Recovery environment, you'll need to add the "/allowfullOS" switch, and basically you would run that command, then reboot straight into your BIOS setup and enable UEFI boot mode (and optionally Secure Boot), because after that conversion occurs, Windows won't boot again until you enable UEFI boot in your BIOS setup interface.
Honestly i am not understanding anything.. i just wanted to install windows 8.1 64bit on my laptop currently it has 32bit but when i try to install it shows some error
Windows cannot be installed to this disk. the selected disk has an MBR partition
@santhirewrote:
Honestly i am not understanding anything.. i just wanted to install windows 8.1 64bit on my laptop currently it has 32bit but when i try to install it shows some error
Windows cannot be installed to this disk. the selected disk has an MBR partition
How hard is it to Google?
.
@ieee488wrote:
@santhirewrote:
Honestly i am not understanding anything.. i just wanted to install windows 8.1 64bit on my laptop currently it has 32bit but when i try to install it shows some error
Windows cannot be installed to this disk. the selected disk has an MBR partition
How hard is it to Google?
.
I know this procedure.. my question is to make it without losing data
Macrium Reflect, even the free version, can convert MBR to GPT even on a system disk, but that's only appropriate if you'll also be switching your system from Legacy BIOS booting to UEFI booting, otherwise your converted GPT disk will be unbootable. The OP saw that error while trying to upgrade from 32-bit Windows to 64-bit Windows, which isn't possible.
jphughan
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Posted April 16th, 2018 06:00
If you're trying to do an in-place upgrade from Windows 8.1 32-bit to Windows 8.1 64-bit, that isn't possible. Switching to a different architecture requires a clean install, so there's no way to do this without losing data. Also, if would have been helpful to mention that you were trying to switch to another OS in the first place.
But if you want to do a clean install, then do this:
- During system startup, press F12 to access the one-time boot menu and boot into your Windows 8.1 64-bit installation media. Make sure you select your boot media under the UEFI Boot Options, not Legacy Boot Options!
- When Windows Setup loads, press Shift+F10 to enter Command Prompt.
- Enter the following commands to wipe your current disk:
diskpart
list disk
select disk X (replace X with the number of your target drive based on the output of "list disk")
clean
exit
exit
- Proceed through Windows Setup. Because you booted the installation media in UEFI mode and now have a totally clean disk, the installer will automatically set up your disk using GPT and create all of the appropriate partitions.