My computer says it has a virus!!!?

My computer keeps flashing a message in my right hand corner. It says that Windows has detected spyware infection. It keeps running a scan from Pest control. It said I have 125 viruses. I bought a internet Anti-Virus program from Walmart (Defender-Pro 5-in-one) Since I installed it the result from the Pest Control Scan has decreased to 115. Does this mean that I installed it correctly? How can I be sure if it is working properly or if my computer is infected still? The Spyware removal wizard still pops up all the time saying that my computer may be infected by malicious spyware, adware, and trojans and it will not let me uninstall the Pest Control Scan. I have gone to different sites I have heard about since I installed the Defender-Pro 5-in-1. The free virus scan and removal tolls I have tried say that 0 viruses were found. Does this mean it's gone!!!!

My computer says it has a virus!!!?avast

Try some of these:

Spyware, Adware, Trojans, Malware, Dialers, Popups:

http://www.download.com/Ad-Aware-SE-Pers...

http://www.ewido.net/en/download/

http://www.javacoolsoftware.com/spywareb...

http://www.download.com/Bazooka-Adware-a...

http://www.javacoolsoftware.com/sgdownlo...

http://www.safer-networking.org/

http://www.download.com/HijackThis/3000-...

http://www.emsisoft.com/en/software/down...