Thank you, yes, I agree and we do use malwarebytes on all 3 of our machines weekly..... we had Spybot, Avast, Adaware and malwarebytes on that Win 7 laptop and hubby scanned every weekend. When the lock up hit it was right after the Adaware download update!...we could not access any scan ware, or icons or get on the net. Putting malwarebytes on a disk or flash would not work. Sometimes we do a trendmicro Housecall maybe once a month, but couldn't do IT because you need the internet for it.
We found the Exploit intrusion using a rescue Windows disc my son made off the net. Windows was still working, so it ran off the CD drive. Even after removal of the 4 Exploits using it, the computer was frozen... because exploit carries other things along with it...and these were invisible to scans.

Now that hubby has restored it we decided to remove spybot and adaware from all our computers. I don't think either one was doing much of anything, anyway. This is the first virus we have ever had... in a decade! Our son said, sometimes if a website is being attacked at the same time you visit it (even if it is a safe one) you can pick up that virus at that time. I don't know how true that is however.