Without the exact name, I can't give you specific removal steps. Go
through these general malware removal steps systematically -
http://www.elephantboycomputers.com/page2.html#Removing_Malware
Include scanning with either Sysclean or Multi_AV, plus Ewido. Do all
prep/finishing work and follow instructions to do all scans in Safe
Mode. Read the rest of the information in the Malware Removal section
at the site and see if any of the specific removal steps match the name
of your rogue antispyware program (Smitfraud, Winfixer, SpywareQuake,
etc.). You can also look on MVP/security expert Eric Howes' page about
rogue antispyware programs here:
http://www.spywarewarrior.com/rogue_anti-spyware.htm
When all else fails, run HijackThis and post your log in one of the
specialty forums listed at the link above (not here, please).
If the procedures look too complex - and there is no shame in admitting
this isn't your cup of tea - take the machine to a professional
computer repair shop (not your local version of BigStoreUSA).
Malke