I just started having the same problem. Mt Avast Pro stopped working, so I downloaded a new copy and it's doing the same thing, only mine mentions PC Cleaner Pro as the "other virus program". I know what it is and I have never had it. I can't find it anywhere on my machine - spent about 8 hours looking. Add/Remove program doesn't show it, Malware Bytes can't find it, search can't find it. Regedit can't find it, and I fired up an old version of Ad-Aware and that can't find it. I tried both regular and sage mode.
When I click continue to try to get it going, it tells me it can't be install in the I selected - I didn't select one yet. This machine is used in a small business and is very seldom connected directly to the net, but I would rather be safe than sorry.
I even tried downloading the free version and got the same results.
Lynn