Make sure that you have a good antivirus installed. Have it update it's viral database.
Get a good anti spyware, install it and have it update itself.
As other sayd, reboot in safe mode.
Start your antivirus to do a full scan. Let it cure any inferction found.
Start your anti spyware. Do a full scan and let it correct any treat found.
DON'T do a system restore, as your check point(s) may also be infected.
MANY virus try very hard to inject themselves into past restore points in a bid to make it's removal as difficult as possible.
Some antivirus propositions (all are free and considered as prety good):
AVG Free at free.avg.com
Avira at www.avira.com
Microsoft Security Essential at www.microsoft.com
I don't recomend Norton. Not to good, very invasive (makes your computer crawl), and expensive.
Electro
April 2011