when I try to unsubscribe to an e-mail ad, it will say subscribtion confirmed then I get this meassage:this program has performed an illegal OPERATION and will be shut down....Kernel32DLL at o167:bff9d709First of all, you don't unsubscribe from ads. If you do try to unsubscribe, they will know your E-mail is real and works.

Second of all, your PC is probably compromised beyond recognition:

Virus scanners
AVG Free
-- Anti virus scanner
Trend Micro Housecall
-- Online anti virus scanner.

Anti spy/malware
Microsoft Antispyware
-- Anti spyware scanner. Windows XP Home and Professional only.
Spybot Search & Destroy
-- Anti spyware scanner
Adaware SE Personal
-- Anti spyware scanner

Firewalls
Use both a hardware and software firewall.
Be advised as dual software firewalls may cause problems

ZoneAlarm Free
-- Free firewall - more USER friendly
Sygate Personal
-- Free firewall - more configuration options

Removal tools
The following files are not substitutes for the ones described above.
They are either diagnostic tools or removal tools for malware of a certain kind

HijackThis
-- Manual malware remover. Post the HijackThis LOG generated only if requested!
McAfee Stinger
-- Virus removal tool. No substitute for a fully functional virus scanner!
CWshredder
-- CoolWebSearch removal tool. Widely known and persistant Hijacker. Quote

when I try to unsubscribe to an e-mail ad, it will say subscribtion confirmed then I get this meassage:this program has performed an illegal operation and will be shut down....Kernel32DLL at o167:bff9d709