Issue converting drive to GPT to use all of the space

[Royal_King]

Hello everyone,

I have a 5 TB drive installed for gaming, and it's currently set as MBR and denying me half my space. The option to convert to GPT is grayed out. Windows 10 is installed on the original drive, and I'm seeing another System Reserved partition on the 5 TB drive. The 5 TB drive is just for running games, so there really isn't any data on that I'd miss if I have to wipe it. I'm not super confident in what I'm doing, so I need some guidance. A picture of my disk management screen is attached.

You guys are the best.

 

[SkyNetRising]

Your partition setup is messed up.
Bootloader should be loaded from F: , but there is another copy of it on C: .

Fix that first.
1. Make partition F: active
2. Fix bootloader on F: (run from elevated command prompt)

• bcdboot c:\windows /s f:

3. Disconnect your 5TB drive and try to boot up your system.
F: partition should have description in Disk Management "System, Active, Primary Partition" now.
4. After that reconnect 5TB drive, delete all partitions on it and convert it to GPT (alternatively you can also use mbr2gpt utility to convert 5TB drive to GPT, that would not require deleting all the partitions, but probably would require more time).
BTW - Disk Management will not allow deleting system reserved partition D: , but you can do that with diskpart utility.

 

[Royal_King]

Your partition setup is messed up.
Bootloader should be loaded from F: , but there is another copy of it on C: .

Fix that first.
1. Make partition F: active
2. Fix bootloader on F: (run from elevated command prompt)

• bcdboot c:\windows /s f:

3. Disconnect your 5TB drive and try to boot up your system.
F: partition should have description in Disk Management "System, Active, Primary Partition" now.
4. After that reconnect 5TB drive, delete all partitions on it and convert it to GPT (alternatively you can also use mbr2gpt utility to convert 5TB drive to GPT, that would not require deleting all the partitions, but probably would require more time).
BTW - Disk Management will not allow deleting system reserved partition D: , but you can do that with diskpart utility.

Thank you for your answer! If it's possible to convert without having to redownload/reinstall the games that would be fantastic. Any tips for using the mbr2gpt utility? Or would I be better off not bothering with it?

 

[SkyNetRising]

Any tips for using the mbr2gpt utility? Or would I be better off not bothering with it?

Command syntax for mbr2gpt utility would be:

• mbr2gpt /convert /disk:1 /allowfullos

You can read help on mbr2gpt utility with command

• mbr2gpt /?

 

[Royal_King]

I ran the utility, but it crashed. The disk seems fine, though. Any ideas? Message said:

MBR2GPT will now attempt to convert disk 1.
If conversion is successful the disk can only be booted in GPT mode.
These changes cannot be undone!

MBR2GPT: Attempting to convert disk 1
MBR2GPT: Retrieving layout of disk
MBR2GPT: Validating layout, disk sector size is: 512 bytes
Cannot find OS partition(s) for disk 1

 

[SkyNetRising]

I guess mbr2gpt utility is meant for converting OS drive only (not secondary storage drive).

There is another software, that can convert MBR to GPT - Minitool Partition Wizard Free.
https://www.partitionwizard.com/free-partition-manager.html

 

[Royal_King]

That worked! Thank you so much for walking me through that.