Whatever you do, do not, I repeat do not download the update for XP called service pack two or SP2. It screwed up my computer something good at work.
If you go to the MSN homepage, the update is sitting right there on the front page, begging to be downloaded.
DON'T DO IT.
Our company's IT group said that they have had to attempt repairs on 5 computers in three weeks that have received the download. After two rounds of repairs, my computer is still not functioning properly.
DON'T DOWNLOAD XP SP@!!