problem is if you just reinstall, i am pretty sure that the drive letter will stay the same. this happened to me once and i went crazy trying to figure out how to switch the system drive back to c:\. you can try using partition magic. i forget the name of it, but there is an app included with partition magic that will change drive letters globially on your system. this isn't on the PM boot disks, only the full windows software.
since i wasn't aware of this app when i had the problem, what i ended up doing was backing up my stuff and just doing a clean install. it was a real pain, but things ran better once it was done and i stopped freaking out once f:\ was returned to the comfort of c:\
in retrospect, it is amazing how conditioned we get in windows about which drive is labeled by a specific letter. one of the clients that i do work for freaked out when after doing a clean install of XP his zip drive, dvd drive and cd-rw all changed letters. I chuckled a bit to myself as i watched him rip down the sticky note on his monitor that was his legend:
c:\ main hard drive
d:\ dvd
e:\ cd-rw
f:\ zip drive
and then he made a new one and put it back where the old one was. He told me that he had just gotten used to where the drives were. you can only image his frustration when i told him i could change them back.
i think that was one of the things that i had to get used to on my powerbook.... no drive letters - just drive names. After a little adjusting, i realized that it totally makes sense. plus if you don't have a cd in the drive, it doesn't appear. when my mother-in-law made the switch, that was one of those things that really took her for a head spin.