Try "Malwarebytes". Install, update, clean house.
Then install the trial of Kaspersky. Update. Update. Scan. clean up.
Should you not be able to install... or they are finding nothing.. then the
Virus has already caused your system to be compromised to the point where
it runs the antivirus programs incorrectly.. or wont allow proper/install.
Best bet then is to use another HD with brand new windows install on it... loaded with updated Kaspersky & updated malwarebytes with all the latest windows
updates. Once thats done.. boot down, stick on the virus drive, and boot up.
Scan and clean.
Once cleaned, turn pc off, pop in original drive, and try. Virus should be disabled
and removed.. but OS still may have holes in it. May have to do an over-install
of windows to refresh corrupted and missing files.
If OS is still corrupted to where its not functioning well.. . transfer your now cleaned data to the New OS HD.
Todays new viruses/root kits are very smart. Ive had them disable Regedit. Disable the Command prompt. Start up running completely in tact in safe mode! Etc. You try to remove them makes them angry and they get 10 times worse.
They remove Dlls. They make it so you cant uninstall programs (so you cant install new antivirus progs) They create Random names and entries, always changing
itself on the fly - so they are never the same each boot. I could go on... but I think
you get the drift heh >.<
Best of luck.