It could be so just to make sure:
For starters, download, update and run a full scan using the following product:
http://www.superantispyware.com/
SuperAntiSpyware is exceptional and will remove the majority of difficult Trojans and Worms, not just the easy ones.
If possible it is recommended that you load the application in normal mode but run it in Safe Mode. Safe Mode can be started by continually pressing F8 during the boot sequence. If you are badly infected you might need to run SuperAntiSpyware more than once to help clean your system. If the only infections now being shown are in System Restore, once you are completely satisfied that you can boot normally, you can either delete the infected restore points manually, or temporarily turn off System Restore.
As I mentioned above no antivirus or antispyware protection is perfect so to make sure you are totally clean download & run SpyWareTerminator
http://www.spywareterminator.com
Okay, we have attacked the Spyware, now its time to have a go at the viruses. Download, update & run Avira. Unlike a lot of the free antivirus applications this one has a comprehensive database and in addition will give you real time protection.
http://www.avira.com
Another equally good choice is Avast
http://www.avast.com/eng/avast_4_home.html
Assuming you have some real awkward infections that persist even after trying all the above I suggest you download a Smitfraud removal program from:
http://www.afterdawn.com/software/desktop_software/desktop_security/smitfraudfix.cfm
If possible run in Safe Mode.
Likewise try VundoFix:
http://vundofix.atribune.org/
Be advised that some infections will corrupt or disable your resident security products so for completeness I have listed a couple of online scans that may help you get started:
Panda - http://www.pandasoftware.com/products/Ac...
Trend - http://housecall.trendmicro.com/
Good luck & safe surfing.
wdw