Well... i don't see a problem here:
he bought the comp at a thrift store... which means the files are unimportant
but...
Where the computer was originally purchased has little to do with which important filse are currently on the computer. However, the person's next post addresses that and they're not important.
Who said he wanted windows? lol
and plus your making a larger deal out of it than necesary...
ive installed Vista Ultimate on 17 different computers in January, and thats a much more complex OS which takes much more time...
then again im a computer geek 
but what anodoin said should work
While not stating it directly, the fact that they're looking to extract the license key so they don't have to purchase another one indicates to me they're looking to put XP back on the machine.
You're right, reinstalling Windows is not that big of a deal, assuming they can get a hold of the same type of WIndows that's on their current machine. Depending on their situation, it would probably be easier to resize the live partitions than tracking down the right version of XP and reinstall.
But the main purpose of me suggesting to use something like Partition Magic is the preservation of data currently on the drives. Since this is not a concern, I would most definately suggest that the harddrives are wiped and repartitioned as it would probably be beneficial for all involved if it was a fresh copy of Windows.
