Split a 1Tb drive in two...simple?

I've got a 1Tb SATA drive in my PC, which came pre-configured with a system recovery partition. The original OS was Vista, but I upgraded it to Windows 7. I'm doing a clear-out, so decided to wipe the drive and start from scratch. I think I've managed to get rid of the recovery partition but, when I go into Disk Management to view the disks, there seems to be an unselectable partition at the end of the drive.

I can't format it, delete it, do anything with it.

I though of leaving it, and adjusting the size of the partitions that were there.

However I've shrunk the size of the first partition, C:, thinking that I could add the additional space to the second partition. But, the drive now has 4 partitions on it...C:, new blank, D:, unknown that I can't do anything with.

Does anyone know what this "unknown" partition at the end of the drive is? Also, can the new partition that has just been created and the space added to the D: partition?

Hope this makes sense?

Duncs

During install you can delete these types of partitions.

When I re-installed it previously, it didn't ask me about deleting them. It just went ahead and installed Windows.

Follow this tutorial: Clean Install Windows 7
When you get to step 7, be sure to click on "drive options (advanced)". That should let you see all the partitions and delete/create ones that you need.

Not at home just now, but will try it later.

Many thanks for your help Havoc.

Duncs