Anyone else run into this much bad luck ?

thedoc46 · 17 Sep 2020 at 22:57

wolfie138 said:
had a bit google of this, and i'm confused. went to the first link i came to
https://docs.microsoft.com/en-us/wi...management/change-an-mbr-disk-into-a-gpt-disk
and in Disk Management, when i click on my OS disk [i have one just for the OS] it says it's MBR and if i right click it only says "convert to dynamic disk", no GPT option. if i go to my other drives, which i use for data etc, they show as GPT partition style.

A dynamic disk allows you to span a partition over multiple drives. So not really what you're looking for. You're looking to convert to GPT. To convert to GPT, unfortunately there is no click, job done. (Unless there's some special software that i'm unaware of which is possible) Doing it manually does require deleting all existing partitions. If you look at their instructions, and if you were using DISKPART, number 3 says 'clean' which is basically deleting all partitions.

At the DISKPART prompt, type list disk. Note the disk number you want to convert.
At the DISKPART prompt, type select disk <disknumber>.
At the DISKPART prompt, type clean.
At the DISKPART prompt, type convert gpt.

I just allowed my Windows installation media to create a new GPT partition for me. As you normally do when you get to the 'Install Now' part of the windows install. However the key is to disable CSM in the UEFI BIOS so it forces Windows to create the GPT and secondly you NEED an entire image backup of your C drive, so you can restore just the partition that Windows is installed on. Typically there will be 3 a system partition, a recovery partition. and the Windows C: partition... its just the C: Windows partiton that you want to be restoring. AFTER you've re-installed a barebone install of Windows.

So to sum things up.

Make a macrium backup of the entire c: boot drive (even though you only need the Windows partition) it'll allow you to restore back to an MBR fully if it all goes south

Download if you don't already have it, a Windows 10 ISO, make a flash drive bootable

Change your BIOS to CSM disabled

Boot from the flash drive with Windows 10

Delete All partitions when it gets to the install windows here, and allow the install to recreate them... THIS is when it'll create the GPT partition across the boot drive

Install Windows

Install Macrium

Do a restore, but only select the c: drive

It'll restart in Windows PE and restore just the Windows partition, leaving the newly created GPT partitions.

You'll now have a fully converted GPT drive with all your old windows settings and install intact.

Hope that helps.

wolfie138 · 18 Sep 2020 at 07:58

thanks for taking the time to type all that up, bud, much appreciated :-)

wolfie138 · 20 Sep 2020 at 13:32

@thedoc46
fyi, i was looking up all this stuff on Tenforums and came across a tool that's now included in the WIn builds that lets you change on the fly, w/out losing data:
https://docs.microsoft.com/en-us/windows/deployment/mbr-to-gpt
i've just tried it, was done in seconds. had a little message saying Reagent could't restart etc, apparently not a big prob, but as i've been getting a solution i've just retried the commands and it seems to have sorted itself.

thedoc46 · 21 Sep 2020 at 04:40

wolfie138 said:
@thedoc46
fyi, i was looking up all this stuff on Tenforums and came across a tool that's now included in the WIn builds that lets you change on the fly, w/out losing data:
https://docs.microsoft.com/en-us/windows/deployment/mbr-to-gpt
i've just tried it, was done in seconds. had a little message saying Reagent could't restart etc, apparently not a big prob, but as i've been getting a solution i've just retried the commands and it seems to have sorted itself.

Cheers Wolfie I didn't know of this command, and will certainly have a play with it in the future. Good find.

wolfie138 · 16 Oct 2020 at 13:21

ok, so i'm getting my purchases together, hopefully will get to build next weekend, can i just double-check some stuff please?
my current Win10 SSD is now a GPT. according to the manual for my new mobo, gigabyte Aorus Z490 Elite AC, most of the BIOS default settings are set-up to use this, the only thing i might have to do is go in and change the boot order, perhaps. so
- do i literally just stick that drive in and boot up and let it do it's stuff?
- do i need to worry about the Windows activation or whatever? I'm using a free upgrade Win10 from a legit purchase of Win 7. Will it ask me for a key again, or just work things out itself? i'm assuming my Win 7 key would still be valid?
- current built has basically just the OS on that SSD, and i have a second SDD split into a couple other drives for my data etc - should i just connect everything up at once, or just connect up the OS drive and let it get settled in before adding the second drive?

TIA.