Unable to extend drive

[UberLoaf]

I am only able to use 2TB on my 3TB hard disk drive. The Disk Management program is not letting me extend the drive past 2048 GB as the option is grayed out. I don't want to delete the partition and have to re-partition the entire drive and lose all my stuff, but I'm told that's the only option. How do I fix this?

[Electronics Wizardy]

You have a mbr partition table, you need to reinitilaze it as a gpt drive and then you can use the rest of the space.

 

Backups? make backups.

[Oshino Shinobu]

The disk is likely set as MBR, you need to convert it to GPT. 

 

Doing this will erase all data on the disk, so you'll want to backup anything you need. Delete the current 2TB partition by right clicking on the section with a blue header and selecting delete. Then right click on the disk (the box with the disk info to the left of the partition sections) and select convert to GPT. 

[meenmeen1103]

Always have backups, a spare drive is worthwhile. Looks like you have about 200gb used on that partition, and you have 179 of free space on C:, so you could save at least a major portion of your stuff by copying it there while you format your 3TB. Better option is to acquire a spare drive first tho. Backups.

[UberLoaf]

Unfortunately I have no backups but thankfully a lot of the stuff I have is easily redownloadable. Thanks guys.

[seagate_surfer]

You can now actually convert from MBR to GPT without necessarily having to lose your data as part of the Windows 10 Fall Creator's Update and newer versions. MBR2GPT is a built-in command line feature now. You will have to run it as administrator. It's still always a good idea to back up, especially when making any kind of system changes, but the basic process is outlined in a support doc from Microsoft:

The command should look something along the lines of:

mbr2gpt /allowFullOS /convert /disk:X

(with X being the number of the disk you want to convert). This should free up the extra space you want to use.

For more info, see Microsoft Support Doc:

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