Larry - There is not a file compatibility issue between Vista and XP, none. Any file that you can save, open, edit, etc in XP you can do the same in Vista. But you need the correct program to handle the file type. As previously mentioned, look at the programs you use (post them here, if you want; look at the links provided by Broni) and make sure there are Vista compatible versions. Word files are
absolutely not an issue.As Broni mentioned, like it or not, XP's days are numbered; do you really want to spend $100 for an 'outdated' OS? ("Sir, I can let you have this 2008 Chevy for $22,000; or, you can have this great 2000 Chevy for $22,100.") If you're not up for a dinner out, put the $100 towards better hardware specs
Btw, for Vista, look for a CPU
at least dual core and
at least 2.0 Ghz (faster is better!), and RAM of
not less than 2 GB (more is better up to 4 GB).
Don't even think about Vista with less than 2 GB RAM.