I haven't tried re-installing.
I have Windows 7 Pro 64 bit. Avast Pro 2015 Antivirus is the product. Is there some other version information needed?
When the box pops up that a scan is beginning...and I click "end". The box disappears. HOWEVER, if I immediately open the interface it shows that it's scanning...despite my selecting to "end" scan. It continues to scan no matter what I do to stop it.
It starts scanning several times a day. I click on pause...and it will. But if I click to end the scan...it acknowledges my selection but it will scan anyway.