I would highly recommend keeping a hardrive that small as one whole drive, no partitions. Keeping programs on a separate partition may decrease your performance. If you you need space for media files (vids, music, etc.) buy a cheapo external harddrive so your main drive can be home to your programs and games, etc.
Partitions are more useful for storing files than programs, because if you have to wipe your windows partition, you will not lose your media files. On the other hand, if you wipe your windows partition and have programs installed on another, you will have to reinstall all of your programs when you reinstall windows.
I've gone through this whole debaccle so I know the pains of it. Anyway, if you're still set on making a partition, leave some 50gb or so on your windows partition for program installations.
Cheers and good luck.