5900x will only boot to windows in CSM mode?

[FarmerGiles97]

So ive recieved my 5900x today and im having trouble booting to windows.

The motherboard bios lets me boot to my ssd in csm mode, but as soon as i turn it off, the drive does not show up under boot options, even though the motherboard detects the drive?

Anyone had any issues with this?

 

[PiKe]

Because your partition format is in mbr and not uefi most likely.

 

[FarmerGiles97]

Because your partition format is in mbr and not uefi most likely.

Ahh, anyway to change it without formatting? And is there any problems in encounter using CSM mode?

 

[stooeh]

you can convert it using mbr2gpt.exe /convert /allowfullos from admin cmd prompt

 

[FarmerGiles97]

you can convert it using mbr2gpt.exe /convert /allowfullos from admin cmd prompt

Getting an error when i try to do it, ill try find a way around it!

 

[stooeh]

Well iirc there is a 3 partition limit - I had to remove my 4th but it only had a couple of games on it at the time.

 

[EsaT]

Here's guide for using that command
http://woshub.com/converting-mbr-to-gpt-with-mbr2gpt-in-windows-10/

Three partition limit comes likely from command accepting only "Primary" partitions instead of extended partitions.
(MBR main partition table accepts only four partitions and that "extended partition" container is used to hold more partitions)

 

[FarmerGiles97]

Here's guide for using that command
http://woshub.com/converting-mbr-to-gpt-with-mbr2gpt-in-windows-10/

Three partition limit comes likely from command accepting only "Primary" partitions instead of extended partitions.
(MBR main partition table accepts only four partitions and that "extended partition" container is used to hold more partitions)

Ive read the article, and im getting MBR2GPT: Disk layout validation failed?

How do i get around this?

 

[EsaT]

There are also other tools for conversion, but most probably allow conversion of system drive only in paid version.
Thous this would apparently work.
https://www.easeus.com/partition-master/convert-mbr-disk-to-gpt-disk.html
According to this limitation of free version is that it supports only up to 8TB drives:
https://www.rizonesoft.com/easeus-partition-master-free-and-pro-review/