UEFI BIOS

RussD

RussD

RussD

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Hi All---I'm a bit Bemused so need some answers Please. I only noticed this the other day.
When I updated my Win 7 to Win 10 over a year or more ago, I never noticed that my SSD was in GPR instead of GPT.

Now what I find Strange is this, My BIOS says UEFI + Legasy in its window. Before the update to 10 I was in UEFI mode, so how did my Bios and SSD choose Legasy?? I did change the SSD from a 240gb to a new 500gb so I guessing that Windows formated it to GPR which made it Legasy instead of GPT.

Can I change it from GPR to GPT without messing up my OS. ?? Or would I be better off buying another 500gb SSD Format it to GPT and clone the old 500gb to it. Then Format the old to GPT then clone the new ssd back to it. THANKS
 
Do you mean MBR and not GPR? Never heard of GPR.

Some mobos with UEFI are capable of running in UEFI and still booting legacy boot record OS drive. If it detects a non UEFI compatible (GPT) boot drive then it will flick to legacy booting. You need to turn off CSM in order to be in a pure UEFI environment. As your drive is not GPT currently nothing will happen and you will just get kicked into UEFI when you reboot with CSM turned off.

You can convert MBR to GPT without losing any data and it can be done using this link: https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10

I actually did exactly this last week as did a bunch of others from the Windows 11 thread. It should take seconds, then boot into the UEFI config screen and turn off CSM so that the system boots into pure UEFI.
 
Hi mrk---Sorry, yes I meant to say MBR. I not got a clue to what CSM is. Not seen it in my BIOS.
I looked in my BIOS and it says UEFI & LEGACY in the Box...Once I have followed the advice in the link above will there be a box for just UEFI or UEFI & Legasy. I Remember with Windows 7 it said UEFI *& LEGASY and booted with UEFI because my 1TB hd was a GPT. Did the same when I first installed Win10 on my First ssd of 148gB. When I updated to a 500GB I forgot to choose GPT. I Hope it does not Mess up my OS & programs. Last time I tried something like this I could NOT boot up to my OS and had to take out the Battery to Reset everything..So Before giving it a go I need to know what CSM is Please...One last thing--I also have 4 HDD in my Desktop. 3 are MBR and one is GPT. Will they still show up and open after I have put my 500GB SSD in GPT. THANKS.
 
The boot record of the other drives doesn't matter they will still show up.

Regarding CSM, it's short for Compatibility Support Module and allows legacy booting of drives that are using an MBR instead of GPT. This is only relevant for boot drives too. You probably won't be able to change CSM to off if the boot drive selected is MBR. All these UEFI/CSM options are setup slightly different between boards too but generally they work the same way and checks are done by the board to avoid issues by enabling one or the other if the boot drive and other devices needed to boot don't support those features.

Converting MBR to GPT in-line like the method in the link has only been possible this way since the October Creators update to Windows 10, so not something you will have seen or tried before.

All you need to do is identify the CSM setting, for it to be there you need to have UEFI enabled first as it may only show up after that, you can just flick through all pages to check it's there somewhere. Then once identified, follow the link's instructions to convert disk 0 (or whatever number relates to your c drive which is disk 0 by default) and run the convert command. Boot back into BIOS and turn off CSM which will then boot into pure UEFI.
 
mrk said:
Do you mean MBR and not GPR? Never heard of GPR.

Some mobos with UEFI are capable of running in UEFI and still booting legacy boot record OS drive. If it detects a non UEFI compatible (GPT) boot drive then it will flick to legacy booting. You need to turn off CSM in order to be in a pure UEFI environment. As your drive is not GPT currently nothing will happen and you will just get kicked into UEFI when you reboot with CSM turned off.

You can convert MBR to GPT without losing any data and it can be done using this link: https://www.windowscentral.com/how-convert-mbr-disk-gpt-move-bios-uefi-windows-10

I actually did exactly this last week as did a bunch of others from the Windows 11 thread. It should take seconds, then boot into the UEFI config screen and turn off CSM so that the system boots into pure UEFI.
Click to expand...
Thanks for the link, that guide was really easy to follow :cool:
 
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