Advice. What brand desktop?
I would lean more towards Grateway or DellHell, and away from EEEEEEEEEEEEEEEEEEEEEEEEEeeeeeeeeee!!!machines or Comcrap.
BUT DO THIS!!!!
WHAT EVER machine you buy, MAKE ABSOLUTELY SURE that you can buy re-install CD/ DVDs and DO NOT swallow the answer that "it has a restore function on the hard drive."
I haven't checked in about 3 years, but GENERALLY you can get restore / reinstall media for free to up to about 40 bucks, depending on the machine. YOU CAN NOT GET these after the warantee ends.
ALSO (my mistake, here) This little Acer which runs Linux, has a Microsh#t license on the bottom of the machine. I didn't notice that it was PAPER and not plastic, so now you can no longer read the key.
If I ever need to reinstall Winhozed7 I just might be screwed.