How to do a super-clean malware scan
No matter how good your security software, and how well you keep it up to date, there's always that nagging doubt: "What if some malicious program is interfering with my antivirus, protecting itself while hurting me?"
That's a legitimate question, and it's one of the reasons I frequently recommend that people use a second malware scanner to supplement their main antivirus program. But even that suggestion involves running a program already installed on your PC (and thus, possibly compromised), while something evil may be running in memory.
I'm going to recommend two ways to scan for infection in a clean environment. Pick which makes the most sense to you, or--if you're really paranoid--use both.