Unable to Expand OS Partition

Ok so I recently got a 2TB HDD and I decided to use it to replace my main drive (Which was a 500GB HDD.) So I cloned my 500GB drive, hooked it up as the main boot drive, and so far it's worked perfectly fine. Unfortunately, I can't extend the main partition to actually use the ~1.4TB that's currently unnallocated. I'm inside the disk manager and the option to extend the main OS partition is grayed out. Oddly enough, the option to extend the recovery partition works perfectly fine. It's very frustrating and I would really appreciate any help.

You could use GParted to create a second NTFS partition and use that if dial manager doesn't work. Just don't GParted to shrink or extend the OS partition cause it might screw up windows.

I forgot to mention that I've also used a 3rd party program to attempt creating a partition out of it and merging it with C: But basically the same problem occurred.

Make sure the drive is a BASIC disk and not DYNAMIC.  Also the Partition windows is on should be Primary not Logical.

http://imgur.com/6SleBhK  Here's what my disk manager reads. It's both a basic/primary disc.

Try running the disk manager as admin

I have been previously running it as an administrator. I also used the Command Prompt method of expanding the disc partition and it returned saying that there is not enough space to expand it, even when I tried 100MB

I'm wondering if something went wrong in the cloning process. Maybe I should try re-cloning it.

Don't take this as gospel - I could be wrong. But it may be that because the OS partition is at the beginning of the drive and the recovery is at the rear next to the free space. At least I would have to make that assumption due to the way the disk manager shows the partitions.
Try to use a Linux live CD or USB to boot the PC and then use GParted to resize. 

Other than that I would use "UBCD" to boot the PC and run a Hard Drive test using MHDD software. Who knows... maybe the drive has some bad sectors on it preventing what you want to do.


Thanks for the responses but I've decided to just use it as a secondary drive and use SteamMover to put my games on there. Probably for the best since the 500 is quieter anyway.