Regarding Fix Me Stick:
I personally don't have experience with the Fix Me Stick, but I can confirm that the professional technicians at the company I work for, use USB sticks and/or CD based tools when trying to scan and eradicate malware. Windows OS has lots of limitations - one of the biggest is; if a computer boots into the OS, there are many places a virus can hide that prevents detection and/or removal. That's why most professional tools boot the computer from a CD/USB, thus preventing the OS from becoming active allowing for a higher probability of detection and removal. <-- fact is most professional techs will run their tools and if a problem still exists: reformat the drive, reimage the OS and reinstall the data from backups. It's simply not cost/time effective to manually remove malware.
"I've never gotten a virus ......"
I hear and read this statement all the time, including here on TERB. I usually respond with "how do you know? Fact is most AV software products only detect 95-98% of malware. Currently there is >>10,000,000 known viruses. Not all are a concern, but there are >200,000 currently undetectable malware payloads and zero-day threats being created every day. Most malware is totally invisible to the PC's user, for example a key logger, port scanner, email relay or even a DOS bot. Some malware limit the amount of CPU, memory and bandwidth they use and can hide themselves in the process table. Some are only active for short periods or on certain days. My point is: 99% of us have no f*cking idea if we have malware or not.
Everybody I'm sure has read about preventing viruses and good pc habits. I'll push two: RUN YOUR SCANS WHILE IN WINDOWS SAFE MODE (better, but not foolproof). If you are bit of a techie, create a bootable Windows CD/DVD and install a virus scanner along with malwarebytes and superantispyware. Boot your PC from the disk and run your scans from it. I'll try to find a good tutorial and post the link in this thread.
"back-up to an external drive and you will be safe"
This is always good advice, although it's not foolproof. Some malware has the ability to attach themselves to applications and files and aren't detectable because the OS/AV is compromised. It's rare, but it's possible. When you copy the file to the drive and back again during recovery .... you are re-infected. In the business world, a common methodology is to back-up to a server or SAN. The server/SAN independently scans for viruses in a virtual protected image (similar to a sandbox if I understand correctly) and since the scan is independent of the compromised PC OS, more viruses can be detected. Not all, but more. ;-)
Also if you simply leave your external drive attached to your PC to allow for incremental backups, a malicious virus could erase it, then your PC and you are left with nothing. External hard drive are unreliable, they will fail eventually.
I use an SSD external drive for weekly backups and I also back-up monthly or as appropriate to DVDs. It's a hassle, but it's safer and provides archival quality storage for my pictures, tax files, etc. Even DVD-R have a shelf life, but it's a good, cheap, safe alternative.
What if a fire destroys your PC and backup drive? Consider an encrypted (on your PC) cloud solution or store your back-up DVDs at another location.