Can't enter UEFI BIOS due to SSD Being MBR

1337x

Reputable
Mar 31, 2015
82
0
4,630
0
In my PC I have an SSD which has my Windows 10 installed on it. In addition to this, I have a 1TB HDD as a second hard drive.

My problem is that I cannot enter the UEFI BIOS because the SSD with Windows installed is MBR instead of GPT. Basically, If I go to BIOS and set UEFI as my boot option, I will get an error saying that there's no Operating system installed and this will cause a boot loop until I set it back to Legacy BIOS.

Is there a way for me to convert my Windows on the SSD to GPT without formatting it and losing my WIndows 10? I don't mind losing information as long as I don't lose my Windows 10.
 

t53186

Distinguished
Nope, If your copy of Windows 10 is licensed and activated you'll just have to reload along with all installed programs. You could and should backup your data. You could clone the drive to your 1TB HSS and restore after loading Win 10 again.

Or you can leave it uset the way it is.
 

1337x

Reputable
Mar 31, 2015
82
0
4,630
0

I don't need to backup anything. My PC is completely empty. I can format it and all of that but I just don't want to lose my licensed and activated Windows 10 on my SSD.

How would I go about converting my 120GB SSD (MBR) to a GPT format so that I can use UEFI? My 1TB HDD is also MBR but I don't really need to mess with that one as it doesn't hold my OS.
 

1337x

Reputable
Mar 31, 2015
82
0
4,630
0


I get this error:
C:\WINDOWS\system32>diskpart

Microsoft DiskPart version 10.0.10586

Copyright (C) 1999-2013 Microsoft Corporation.
On computer: MyPC

DISKPART> list disk

Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 931 GB 1024 KB
Disk 1 Online 111 GB 0 B

DISKPART> select disk 1

Disk 1 is now the selected disk.

DISKPART> clean

Virtual Disk Service error:
Clean is not allowed on the disk containing the current boot,
system, pagefile, crashdump or hibernation volume.

Disk 0 is my 1TB HDD and Disk 1 is my 120GB SSD (With OS installed)
 

misar

Proper
Sep 25, 2018
62
0
160
8


Yes. As it is Windows 10 you can use Microsoft's free mbr2gpt.exe tool and convert the system disk w/o any loss of data or need to reinstall Windows:
https://www.thewindowsclub.com/mbr2gpt-tool-windows-10
 

1337x

Reputable
Mar 31, 2015
82
0
4,630
0


If I shutdown the PC, reboot and then press F1 to enter BIOS, it goes to Legacy BIOS and if I scroll through the menu and select UEFI as the default boot priority, the PC won't launch the UEFI BIOS at all. It goes straight to the screen saying: "Error 1962: No operating system found". If I then try to get into BIOS, it goes back to Legacy BIOS and not the UEFI BIOS I selected.
 

misar

Proper
Sep 25, 2018
62
0
160
8


Its doing that because an MBR system disk requires the legacy BIOS!
You need to convert to GPT first.

 

karenjoly

Respectable
Apr 13, 2018
1,329
19
1,815
166
Misar above has it correctly. If you want to convert the disk, you can do so without the need to reinstall. Any advice to the contrary is very dated and incorrect.

Use Microsoft's free mbr2gpt tool.

Read the document here for usage, conditions and prerequisites. The app is in Windows\System32 directory on a computer running Windows 10 version 1703 or later.

"It converts a disk from the Master Boot Record (MBR) to the GUID Partition Table (GPT) partition style without modifying or deleting data on the disk".

https://docs.microsoft.com/en-us/windows/deployment/mbr-to-gpt

Now about the message from diskpart ( why did this get used ?) It is a very dangerous app. It would wipe a drive . As you tried to do . Luckily that did not succeed. See the exact words. You tried to "clean" the C drive. The only reason you did not blow away your OS is that , under some mercy guidance, Microsoft protects those files from dumb moves.

The message says Virtual Disk Service error:
Clean is not allowed on the disk containing the current boot,
system, pagefile, crashdump or hibernation volume.

Pat yourself on the back. You just survived a monumental mistake.

 

1337x

Reputable
Mar 31, 2015
82
0
4,630
0


I am busy updating my Windows to the latest version so that I can get that MBR to GPT tool. Should I only convert my 120GB SSD (With OS installed) to GPT or should I convert both drives (My SSD and 1TB HDD)?

Haha yeah, that would've been a mistake if it worked. I followed the 1st link above which took me to a Microsoft site and had that guide.
 

karenjoly

Respectable
Apr 13, 2018
1,329
19
1,815
166
Convert the boot drive. The HDD's partition scheme doesn't matter, MBR/GPT, both are good for storage/ non boot drives.

You do not say whether the SSD drive boots into the OS when the board is left on legacy. Does it ? It should. So why UEFI ?
 

1337x

Reputable
Mar 31, 2015
82
0
4,630
0


It boots fine with legacy BIOS. I am able to get into and use Windows perfectly however, my problem arises when I need to make changes in the BIOS such as for RAM etc. Legacy BIOS doesn't display any information I need in order to tweak things.

http://www.tomshardware.com/answers/id-3814897/ddr3-ram-displaying-1600mhz.html

The above link shows you my problem I have with RAM and someone suggested that I get into the BIOS and change the XMP Profile to 1. Since I didn't put any of information onto this PC as yet, I figured I should set it up properly now instead of putting all my files here and then tweaking it and experiencing problems later on.
 

1337x

Reputable
Mar 31, 2015
82
0
4,630
0


I have done the conversion and it has completed successfully however, I am still not able to boot into UEFI. I can still only boot into Legacy BIOS even though I specified UEFI ONLY in the BIOS settings.

Side note: After converting to GPT, I know have an additional drive showing up as 'System Reserved'. Is this normal? Can I remove it?
 

karenjoly

Respectable
Apr 13, 2018
1,329
19
1,815
166
Why not start a separate topic leading with system specs, a picture of the Disk Management screen, a brief history of the drive, the problem you have booting and the question about the new " drive".
 

Colif

Titan
Moderator


If your PC has a choice called UEFI boot, it is already showing you the UEFI bios. It won't look any different to what you already had. All motherboards in last 9 years have had UEFI bios.

Its like this, any BIOS that allows you to choose a legacy option is a UEFI bios already, as prior to UEFI there was only 1 way to format hdd, so it wouldn't offer a choice.

https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface

You don't have two BIOS, legacy & UEFI., You have just the one, its just UEFI can emulate the BIOS features so older systems such as Win 7 can be installed on it using MBR, and not notice any differences. UEFI is so much more than BIOS, it has features BIOS didn't and is by design modular so it can be altered to grow as PC need more features. Also lets you have a Graphical User Interface in the "bios" that knows what a mouse does.

What you did was swap from legacy boot method to UEFI boot method, it didn't change the BIOS itself.

I wish I had seen thread prior to you following the advice as you already had what you wanted, you just didn't know it. Shame no one else thought about it either.

GPT also isn't of great benefit to the disk sizes you have, its main advantage over MBR is it can access drives bigger than 2.2tb (much bigger, 18.8 million Terabytes is the max size it can access, largest drive now is a few 100 terabytes in size). I mean, its not a bad choice but only as now you can have up to 256 partitions on the drive if you wanted, MBR only allowed 4.

System reserved isn't a new drive, its a new partition probably created during the GPT conversion

show screen shots of disk management here (upload to a image sharing website and share links here) instead of new thread as it shouldn't have a drive letter, so should only show in disk management.
 

misar

Proper
Sep 25, 2018
62
0
160
8


I think the OP wanted to change to a GPT disk in order to boot from UEFI mode instead of legacy BIOS mode in the expectation that the former allows more BIOS options/settings than the latter. You seem to be viewing the issue the other way round.
 

Colif

Titan
Moderator
@Miser, the below quote seems to indicate he thought he would get a new BIOS if he swapped from legacy to UEFI boot, My main point was he was already in UEFI bios, it was just emulating the legacy bios boot method.

I swapped from legacy to UEFi Boot method myself 3 weeks ago and as far as I can tell, the only big change between both was I may have an option called UEFI Firmware interface in my Advanced menu of Advanced Startup. Not something I had missed until I went to clean install win 10 on an MBR syste,



 

ASK THE COMMUNITY

TRENDING THREADS