After a bit of trouble, I've managed to clone my old HDD onto a new one and get Windows to run off of it. And as far as I know, that should've turned the new drive into the C: drive, but it didn't. It's still "D:", even though it's (according to the computer) being used to boot and run Windows.
Changing it directly through the disk & partition manager isn't allowed (the C: drive cannot be changed), so I'm at a bit of a loss.
Changing it directly through the disk & partition manager isn't allowed (the C: drive cannot be changed), so I'm at a bit of a loss.