1- If you have anti-virus and anti-spyware programs already installed on
 your computer, update the programs and scan your computer. With luck,
the programs will detect and remove the problem.

2- If the scan doesn't produce results, contact the program's technical
support. Most of the major anti-virus/spyware programs will help you to
remove an infection that their software did not detect.

3- Scan your system with /several/ of the better free online scanners,
such as (no order implied):

Kaspersky Antivirus (http://www.kaspersky.com/virusscanner)
NOD32 (http://www.eset.com/download/index.php) - free 30-day trial
Trend Micro Housecall (http://housecall.trendmicro.com)
Panda ActiveScan (http://www.pandasoftware.com/activescan)
Sophos
(http://www.sophos.com/products/free-tools/sophos-threat-detection-test.ht
ml)
Avast! (http://www.avast.com/eng/avast-virus-cleaner.html)
GrisSoft AVG (http://www.grisoft.com/doc/34/ww/crp/0)

4- HijackThis is a hijacker detector and remover, but expanded with a
lot of other checks against hijacker tricks. It is continually updated
to detect and remove new hijacks. More information here:

http://www.whatthetech.com/hijackthis_v2/

You can post your HiJack This logs in several forums (NOT here), such as
 this one:

http://forums.whatthetech.com/HijackThis_Logs_and_Infections_Removal_f27.h
tml

If none of the above remove the malware, you may want to show the
computer to a professional.

There may be nothing you can do to remove an infection, no matter what
you  try. That's because some infections compromise your computer to the
point  where you can no longer rely on what the operating system is
telling you.  Rootkits are an example of this kind of infection. In that
case, your only way out is to erase your hard disk and reinstall
everything from scratch.

"Help I Got Hacked. Now What Do I Do?"
http://www.microsoft.com/technet/community/columns/secmgmt/sm0504.mspx

"So how did I get infected in the first place?"
http://forums.spywareinfo.com/index.php?showtopic=60955

---
Leonard Grey
Errare humanum est