Please tell me solution of this mesg. this mesg. appearing after 2 min. in windows xp desktop beside the Time. I have used many anti virus, and registry cleaner, anti malware, anti spyware, but this message not going. if i click this message then open a antispyware web site. please help me.. i am very confused, t will be very thankful to any body who give me proper solution.

CRITICAL SYSTEM ERROR ! SYSTEM detected virus activities, they may cause critical system failure,Please use antimalware software to clean and protect system from parasite program. click here to get available software