I've used Ewido quiet are few times in the last year. Usually when I get to a somebodies house and find out its not just infected with Spyware, the Spyware is practially the O/S
It takes a long time, but its scans it runs are very effective and 9 times out of 10 it was all that was needed to clean the PC. Some of the pop-ups are very annoying though, and the fact that it was a 30 day trail, meant iv'e only ever used it to clean a PC once, never on a constant bases.
If its the full version (cant check at work) I'd installed it since its saved my rear end a few times already