Hi, and welcome to BBB. Download Spybot Search and Destroy
here, install it together with the latest updates, and do a complete scan of your system.
Super Antispyware is another good antispyware program. Download the free version and its updates, and do another scan after Spybot has finished. Unlike antivirus programs, you can have more than one antispyware program present in your system.
As an added security measure, you should also scan your system for viruses after this. There are many good online scanners available for free, try the ESET online scanner
here.
If you don't currently have an antivirus program in your PC, I'd recommend AVG7.5 Free, obtainable
here. However, ensure that you have only one antivirus program resident, otherwise there are bound to be problems.
Good luck, and please post back to let us know how it goes.