I fix computers daily, it's my business. You guys got it right. Ad-aware is great. Update it and run it. Microsoft Anti-Spyware is great, and runs live, so you get alerts when spyware attempts to install itself ... very worthwhile. Also, it auto-updates and scans.

Firefox -- my fav. Plus it's fairly impervious to most of the spyware/adware tricks.

Running Windows XP, get all your updates, esp. SP2 -- that's got all the BIG security fixes.

Getting an infected PC can be tough. Try running your ad-aware in safe mode if it keeps locking up during scanning. You may need several anti-spyware apps if things are really bad. In addition to those already mentioned, Spyboit works okay too -- personally don't like it too much.

Lastly. never click a pop-up ad. If there's no "X", use [ALT]-[F4] to kill it