Yes...
It is better to partition the hard drive...
I don't know if windows 7 will allow you to do this, I don't use 7...srry on that note.
Carrying around a few extra external HDD really is a good idea..on paper, but the reality is, it is more cumbersome then it is really worth..
My personal setup, is a compaq presario, I remover the 160GB and installed a Seagate 750GB for a $100.00. then I partitioned it X3..
100GB for XP-Pro, 100GB for Vista Ultimate and 300GB for misc/games..
I truly hope this helps in any way..
here is the link for the HDD..[http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=6324326&CatId=2682]
Good Luck, Happy Thanksgiving...