this aint really going to answer your question but my advise is this…
basically install windows xp with sp3 etc and setup all your main apps and then use something like Ghost and make a image of your C drive. so this way say 1 year down the road windows gets messed up etc etc you can just restore with that ghost image back to the point of a fresh installation… thats actually quicker in the long run vs reinstalling xp everytime.
ghost costs money but there are free linux based drive image apps like PING ( http://ping.windowsdream.com/ping/download.html ) etc etc that do it for free.
i used PING myself and it’s pretty straight forward and overall easy to use… but i have never actually restored a partition with this yet but im sure it will be fine.
but if your going to format my advise is this…
partition your hard drive with 2 partitions like say a C (about 10-15GB) and the rest goes on D… im just assuming you have one hard drive. … so this way you can install all your basic apps etc etc to C and anything large like games etc can install to D… so this way when you defrag the main OS partition it goes quicker and when you format the games will still be on D… plus with that PING app you can image the C partition to the D partition.
just some thoughts, good luck