A popup appeared on my computer from something called "Fast Windows" - apparently Microsoft security, but I don't know - saying I'd got several viruses, which it listed. It invited me to click on a button to remove them, but the button seemed to be inactive. I did a scan with AVG (quick one, not the deep scan) and it found no viruses. Is this a scam or is there a real problem?
I've done that too, thanks, VHG; it also found nothing. But what about "Fast Windows" itself - does that not count as a virus? I don't know where it came from; the only thing I had open at the time was Google.
>> most scams are written in pidgin English or Nigerian or something
Not true of many of these spyware scams on computer.
They often look and feel like "real" pieces of software and can fool even the most experienced of us.
These malware / spyware scams are becoming more and more common, more and more aggressive, and harder to get rid of. Some even hold the data on your PC to ramsom unless you pay them the money (they say them will delete your data off your PC if you dont pay)
If Malwarebytes didn't find anything, and you are still getting the popups, try Superantispyware - it sometimes finds things MBAM misses. Download link is http://www.superantispyware.com/download.html
It's a fake virus scanner that reports non-existent infections. Fred Langa wrote a good story about such misleading online virus scanners: http://windowssecrets...blow-by-blow-account/
A good write-up with with a screenshot of Fast Windows Antivirus 2011 scanner:
If you didn't download anything from that web page then I think your PC is clean. To make sure that it's really clean, scan your computer with anti-malware software. I usually use Hitman Pro and Malwarebytes.