Windows 10: Partition Prerequisites for converting to GPT using MBR2GPT

Hi
I am looking into converting from a BIOS based system to UEFI using MBR2GPT but I understand there are specific rules for the layout of the system disk. Currently I have four Primary partitions comprising System Reserved, Windows 7, Windows 10 and an unnamed partition which I believe to be the Recovery partition. Should I decide to go ahead then Windows 7 will come out but what of what is left?

In searching out info before making my decision I found this site:

UEFI/GPT-based hard drive partitions
Now I understand there have been a number of folks on this forum who have had problems because their partition layout before starting their conversion using MBR2GPT was incompatible with UEFI. Could I therefore ask Brink or someone else with knowledge on this topic to please give us some idea of the prerequisites re partitions (and indeed anything else) for the conversion including partition sizes since I understand the MSR partition MUST come between the System Reserved and Windows partitions as stated in the item above.

Any help would be most appreciated.
Tracey

PS I include below my disk layout more specifically my System disk layout as of this moment for any comment but please bare in mind that Windows 7 will come out.





:)

 

Installing Windows 10 on PC with a recovery partition.

Hi Andre Da Costa !

My PC's BIOS automatically came with UEFI turned on hence there were no boot options to select from.(No USB/DVD ROM). Hence I went to legacy mode using command prompt completely formatted the drive ,convert to GPT to
MBR wrote the OS and converted the MBR to GPT using MBR2GPT. Finally changed the BIOS to UEFI problem solved.

Thanks and Regards,

Buwaneka.

 

Windows cannot be installed to this disk.

MBR2GPT < Go read that page.

Windows has mbr2gpt.exe in the system32 folder & actually it can be run from booted media or within windows to convert to a uefi gpt layout. But you need some reading first.

 

Hi, here's Brink's tutorial.
Convert Windows 10 from Legacy BIOS to UEFI without Data Loss Installation Upgrade Tutorials
But it looks as if you're dual booting, and the tutorial says

Another:
Convert MBR Disk to GPT Disk in Windows 10 Hardware Drivers Tutorials

 

The main issue is your boot drive already has four primary partitions and it looks like you are dual booting anyway.

I recommend you back up all data on Windows 7 partition and remove it and the system reserved partition, then use mbr2gpt, then reinstall windows 7 from scratch (you will need to disable secure boot to install it in UEFI mode.

 

Hi Guys

Thanks for your replies but I don't think you've really read my post. If you read it carefully you will find that I have said that "Windows 7 will come out" and I also asked readers to bare this in mind. To put it another way, Windows 7 will be taken out before I try the conversion so I will therefore have only three Primary partitions when I try the conversion.

All I am looking for is clarification of the prerequisites for doing the conversion but please, if you are going to make comments on my system disk layout, please be sure you read my post properly and if there is anything you are not sure about then ask, please!

Tracey

 

I did, and given your comment, will leave you to it. Good luck!

 

After you delete the Windows 7 partition, make sure you also delete the boot entry for it from the BCD. (bcdedit commands). Then give the MBR2GPT command a try. Keep in mind whenever you do anything like this there is always a chance you will lose everything, especially on the drive being modified, so I would make sure to have a backup created of whatever you cannot afford to lose.

I believe the first thing MBR2GPT is going to do is verify the disk layout is acceptable to it for conversion and it will just tell if it isn't before it does anything.

 

Hi

Thanks for your replies. Dalchina sorry for my comments. Having had another look at my post I guess I could have made it absolutely clear by adding "before conversion". Sincerest apologies for my attitude and my omission.

I have anyway found another reason not to do the conversion, at least not yet. This is that I do NOT have a UEFI enabled graphic card as I'm still using a GTX260 which is several years old and was produced before UEFI was adopted. In addition, having had a look last night, it seems I do NOT have the option to disable Secure Boot. As a result to do what I want I have to get a UEFI enabled graphic card, at least that is my understanding anyway. We'll see what turns up on Black Friday -- unless anyone here knows of any way I should be able to do it with a GTX260 but bare in mind my comment re Secure Boot.

Tracey

 

Another question becomes exactly why you were wanting to enable UEFI booting anyway? What did you want to accomplish with it? The biggest advantage to UEFI booting is the ability to boot a GPT partitioned drive to enable more than 4 primary partitions on it. Was that your goal, to have more than 4 primary partitions?

 

Hi

I realise you can have more than four primary partitions but I've been told it goes a bit further than that. I understand that you also have enhanced security and an increase in booting and shutting down speed (not that either of them are important to me). You know, I'm now asking myself if the enhanced security is in itself enough reason to move to UEFI and is it likely to cause more trouble getting it up and running than it is worth. At present my PC works fine in BIOS mode and my old GTX260 does everything I want it to so do I really need to convert to UEFI. What do you reckon?

Tracey

 

Well done for apologising. People here bend over backwards to help.

I am confused by your post. Do you mean a UEFI enabled motherboard, not graphic card.

The graphic card has nothing to do with whether pc uses legacy bios or UEFI.

Tell us what exactly you are trying to do and why?

 

The difference in startup and shutdown times will be at most 1 or 2 seconds. The enhanced security feature of UEFI is mostly secure boot which will only boot an OS that has the digital signature associated with it to define it as "genuine." Those "benefits" of UEFI over legacy BIOS alone just would not make it worth it, in my opinion, to mess with upgrading the drive to GPT partitioning and UEFI booting.

Now, I have a bit of OCD. It would just bother me a little bit in the back of my mind to know my computer was UEFI capable and I was using a "compatibility mode" to turn off UEFI and be booting in legacy mode. So, only because of my minor little "disorder", which also means I don't like burned out light bulbs in my house either, I would convert the drive to GPT and UEFI booting. But I would do it manually and not use MBR2GPT. It is extremely easy to backup the OS partition (and any data partitions on the drive). Wipe the hard drive and set the blank drive to GPT. Create your own EFI System Partition. Restore the OS and data partitions. Then create the boot files in the EFI System Partition with the bcdboot command. Everything except the actual backup and restore of the OS and data partitions I can do now from memory in less than 2 minutes.

 

Thanks for your replies folks.

Cerebus -- I have seen posts elsewhere (not sure I could find them now but they are there) which say quite clearly that if you have a non-UEFI enabled graphic card your and you convert to UEFI your PC may not boot. I've also seen it said that you DO need a UEFI enabled graphic card. Now you come along and say the graphic card has nothing to do with it and I'm getting confused now. Please don't take that the wrong way but can you see why I'm getting confused. You say the graphic card has nothing to do with it -- so therefore you are saying I should have no trouble converting to UEFI mode with my old GTX260.

Basically I've been told that BIOS is old technology and I could be better off with a system which allows up to 128 primary partitions per disk. What my aim is is to get up to date by converting to UEFI.

NavyLCDR -- You say you would do the conversion manually rather than with MBR2GPT. I hate to ask this but since you know an awful lot more about it than I do, any chance you could detail the procedure with commands I'd need to use so I can make up my own mind as to which method to use.

Also, could I ask your opinion re the graphic card question to help clear up my confusion on the matter? Can I use my old GTX260 or will I have to get a UEFI enabled card? Sorry Cerebus but I am so confused on this.

Tracey

 

@cereberus is absolutely correct. Look at my System Specs, I am using exact same model NVIDIA GTX260. So where ever info you get from is wrong.