Windows 10: Games keep crashing after changing my disk to GPT and BIOS mode to UEFT

I changed my disk type from MBR to GPT and changed my BIOS mode to UEFI and my games keep crashing after changing. Can anyone please help me fix this problem?

:)

 

No boot disk found after converting disk to GPT

I have saved my data so I am fine with the data. When There are only 3 primary partitions and no other partitions I have converted MBR disk to GPT. Then went to BIOS and changed Legacy mode to UEFI mode. Thats when I observed UEFI mode didnot he any
boot options listed. Anyway I booted the notebook, as I was expecting, I got the error message. No bookable disk. Is there anyway we can get boot options to UEFI Mode? If not through cmd using the instal disk can we change the disk type from GPT toMBR without
losing windows. If not I just have to install windows afresh!!

 

How to convert an MBR disk into a GPT disk

Hi,

Thanks for the reply.

This is an unexpected behavior, after you convert the disk from MBR to GPT, it shouldn’t convert back automatically, however you can try to convert the disk back to GPT format if you are on Windows 10 version 1703 or later using the inbuilt utility
MBR2GPT.EXE.

• Click on Start menu (Windows logo), type
  CMD.
  
• Right click on Command prompt and select
  Run as administrator.
  
• Type MBR2GPT /validate /AllowFullOS
  
• Once the validation is successful, execute the following command and check the results.
  
• Type MBR2GPT /Convert /AllowFullOS
  
• Once the conversion is successful, you must boot the computer into BIOS and change the BIOS mode to
  UEFI.
  

Disclaimer: Modifying BIOS/ complementary metal oxide semiconductor (CMOS) settings incorrectly can cause serious problems that may prevent your computer from booting properly.
Microsoft cannot guarantee that any problems resulting from the configuring of BIOS/CMOS settings can be solved. Modifications of the settings are at your own risk.

For more information about MBR2GPT utility, please refer to the article:
Convert MBR disk into GPT using MBR2GPT.EXE

Hope it helps.

Thanks,

Peer Samie

Microsoft Community-Moderator

 

Converting a MBR disk to a GPT disk

When installing Windows I was asked which drive to install it on and selected the 3TB drive, whereupon it stated it couldn't install it on there as it had a MBR and needed a GPT drive.

-> OK, with such a large disk you must use the GPT partitioning scheme.

I then tried converting it to a GPT drive using diskpart etc through the Cmd prompt with Admin privileges. But when I got to selecting the disk it told me I couldn't select it because it had a Paging
File.

-> I am not surprised.

Went online to get MS Technician to help me and he said go into the BIOS, press Ctrl-Shift-Delete keys and then Diskpart etc to convert the disk to GPT.

-> What he probably said is that you need to set the "BIOS boot mode" to UEFI.

The Windows installation process gives you the option of partitioning and formatting your disk. It probably lets you choose the partitioning scheme too, MBR or GPT. I do not know for sure since I do not
have a disk > 2 TBytes that I could test. If not then you can do this:

• Boot the machine with your installation medium.
• Select Repair Mode, then the Command Prompt.
• Use diskpart.exe to partition & format the disk.
• Install Windows.

You might ask yourself if you really want a 3 TByte System Partition. I would go for a 100 GByte System partition and a 2.9 TByte data partition.