Run a full scan with malwarebytes while in safe mode...
You'll be best off using another computer to download the file in the link below and put it on a usb memory stick, or CD. Then start the computer with the problem in safe mode by switching it on and tapping the F8 key straight away. When you get the boot menu select safe mode with networking. Once the computer is started install malwarebytes from the USB stick, or CD and let it update (if you have a earlier version of windows than windows7 wireless won't work for this step, you'll need to connect by Ethernet cable). Once the program has installed and updated run a full scan with it and remove anything it finds.
http://download.cnet....-8022_4-10804572.html