Download and install, and update Malwarebytes and "Spybot Search & Destroy".
Then reboot your computer, and start up in Safe Mode.
Scan your system with the above 2 programs, and your Anti-virus while in
Safe Mode.
All info below.
http://www.spybot.info/en/index.html
Spybot Search & Destroy 1.6 is a very good, FREE Anti-Spyware Program.
Download, install, update, and immunize your System with it.
Then SCAN with it.
Update it, and scan your System once a fortnight.
http://www.malwarebytes.org/mbam.php
Malwarebytes is as the name says, a Malware Remover!
For the Free version scroll down their page to either download from
Download.com, or Major Geeks.com
Download, install, and update.
Important re: Safe Mode
If you happen to find a problem that you can’t uninstall / delete, reboot
the computer, and go into Safe Mode.
To get into Safe mode, tap F8 right at Power On / Startup, and use UP arrow
key to get to Safe Mode from list of options, then hit ENTER.
RESCAN your computer with your Anti-Virus, Malwarebytes and Spybot S & D
while in Safe Mode.