12 Apr 2007 at 16:54 - 10
Tundra,
Understand something very basic: Unless you've done a lot of downloading (especially Torrents and the like, which may be of... questionable... legality), you're probably not at great risk. On the other hand, if you (or your friend) have engaged in a lot of downloads, there's a chance - a chance, only - that you may have an infected system.
SpyBot, AdAware, and Avast! Antivirus are good tools, with free downloads, and do a very good job of keeping a system clean; I would recommend a Google search for each.
The ONLY "safe" system is one that is totally unplugged from the wall and off. All that we can do as users is take reasonable measures to prevent loss, and the tools above are some of those measures.
Many banks have a limit to liability for customers in the event of credit fraud, so check with your bank to see if you are protected in a similar manner. I believe for US customers, it's over $50 - you pay anything up to that, but beyond that you don't. (It may be different by state.)
Anyway, good luck. The ArenaNet store in GW has been fine for me; no problems.