Convert MBR to GPT without Data Loss

NettleWarbler

Honorable Member
I tried Uefi custom install , tried to delete the partitions 2 were greyed out i could'nt delete them . Now all i'm getting on my main hard drive is reboot and select proper boot device , that must be with deleting the partitions . The sizes shown that i could'nt remove were 2048GB and 14716GB .
 

kemical

Windows Forum Admin
Staff member
Premium Supporter
Did you change your boot order so that you booted from the media windows is on?
 

kemical

Windows Forum Admin
Staff member
Premium Supporter
I selected Uefi mode and tried to delete the partitians 2 were left
Hmm that's not what I'm asking, did you boot from the media windows is on?

It doesn't sound like you did otherwise you would be able to delete those partitions.
 

kemical

Windows Forum Admin
Staff member
Premium Supporter
There were 2 modes legacy and uefi i selected uefi ( clicked on it so that was the only option ) then tried to delete the patitions .
I assume you mean in the bios?

You then need to boot from the media windows is on.

Start the install process and find the drive you want as your boot drive.

You then delete all partitions and click next.

Windows will install to gpt partition.
 

kemical

Windows Forum Admin
Staff member
Premium Supporter
When i tried to install windows there were 2 partitians left i could'nt delete ( greyed out ) , which meant i could'nt install .
Can you describe what you actually did to get to the above point please.

I keep asking if you booted from the media windows is on and I wonder why you keep ignoring my request.

As you asked above on how to boot from install media I now doubt this is what your actually doing.

If your simply rebooting the machine with the install media inserted then that won't do it, you have to tell the system (bios) to boot from either the disk or usb windows is on. This is so you can have full access to your boot drive otherwise you can't delete partitions ect..

This is usually a relatively simple process.
 

NettleWarbler

Honorable Member
When i clicked disk management , right clicked the disk and selected convert to gpt it did . I converted it before but failed to initialise it . Theres still windows to load .
 

NettleWarbler

Honorable Member
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kemical

Windows Forum Admin
Staff member
Premium Supporter
I watched your video and i use exactly the same process except I do not use the commands shown. I simply delete the partitions and click next.

I have a feeling part of your issue is the size of the drive. Over 2.2TB the drive needs to initialized to GPT first before it can used as a boot drive. Thats why in your screengrab you see a partition of 2TB and then the unallocated section because mbr can only handle 2,2TB.

Do you have a different, smaller, drive you can pop windows on and then format the big drive to gpt?

Further reading:
Windows support for hard disks exceeding 2 TB - Windows Server
 
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