REFORMAT GO

Ok, I have a very blatant and very annoying virus. No scanners pick it up, I can't find a firewall tool that finds logs for the virus reporting back to anyone, and it pops up every half hour to 45 minutes as an unnamed, un-icon'ed program in the taskbar for a fraction of a second. However, when it comes up, it focuses the desktop on that program...if I'm playing a game and DirectX does not have control of the display directly (i.e.: menus), it will swap to that viral program. But that's not the case.

I've decided that I will scan all my data twice over and reformat my system hard drive. I've also heard that keeping system images of a pristine installation of XP is a good idea. So...
I think I will move all of my C: data to a secondary HDD and reformat my system drive. Should I make a partition *just* for XP and partition the remainder for actual data? And is there any way I could do an XP reinstall without moving everything? I've heard of such a possible method, but I doubt if I could repartition the drive....so I prithee! CAN I MAKE AN XP AND XP GHOST IMAGE PARTITION WITHOUT HAVING TO MOVE DATA!? (Probably not, so...) What size partition will I need to reinstall XP to? Any websites out there that might describe the process of such a technique?

The "99%" of searchable questions are asked here (and EVERY OTHER COMPUTER DISCUSSION FORUM ON THE INTERNET) simply because someone who's inexperienced likes to know that someone who is more experienced either agrees with them or has a better suggestion for their solution.

Not that anyone trolling comp looking for "gb2google" posts would know about personal interactions of the sort.