Personal Antivirus is a fake spyware and virus remover, that is a
program that tries to convince you into buying it by providing fake,
unrealistic data about your PC infections or by using trojans and
other parasites to promote itself. Personal Antivirus is distributed
by malicious infected web sites that provide fake “computer antivirus
scans”, malicious software bundles, for example fake codecs, fake
shareware, or are downloaded by trojans already installed in your
system. In the last case, trojans in your system get a signal to start
promoting rogue applications like Personal Antivirus, from botnet
owners that in fact control your PC. You start seeing various popups
describing grave state of your system and that you need this
“wonderfull” Personal Antivirus, that is “recommended by Microsoft”..
That is utter lies - Microsoft does not recommend this scamware.
TO remove personal AV virus from your pc, follow the removal
instructions within this link
http://darfuns.com/spyware-removal/personal-antivirus-fake-spyware/