widgetguy_th :
If I do end up reformatting the partition with windows 7 on it, will I only have to reformat that partition or do I have to do the whole hard drive?
Yes.
You'll see many arguments against partitioning but never on that topic .....there's no arguing the point that replacing on OS on a partitioned drive is much easier than a non partitioned one.
Another advantage is that HD's are about 2 x faster at the outer edge than they are at the inner. So it allows you to "plan" where you want things stored and keep them there.
When I reinstall on OS on a C partition, I either image it back off an image at the end of the drive or reinstall from scratch. The latter of course won't leave all your programs in a working state because the registry entries and common file have not been installed. Some will work, some will not. However, you are still ahead of the game as any customizations will remain intact as "installing over" the previous installation won't replace any modified files.
You can also create a small D:\ Partition for swap and temp file usage. This keeps them at almost the very outer edge of the disk where ya get that high DTR. Dropping the NTFS overhead by formatting this partition as FAT 32 also gives a small boost; NTFS file protections are kinda unnecessary for temp files.
E:\ should be programs or games depending on your speed priorities, with the other following immediately behind. Data partitions I put at the end unless there's gonna be a last partition reserved for backups