Having taken a quick peek, I see two issues that are of concern:
1) The PC only has Service Pack 2 installed - that's one behind what is available. Given that the machine isn't fully up to date, it is at greater risk of infection due to holes that Microsoft will have identified and released patches for but which you don't have. That isn't good, but it isn't terminal, unlike number 2.
2) I see no firewall or anti-virus present - Microsoft AntiSpyware is the closest security you have, and it isn't sufficient.
My usual response to this situation is something along the lines of:
Given the lack of basic security programs onboard the best suggestion I can offer is to back up any important files and then reformat and reinstall Windows.
It is going to be impossible to guarantee a clean computer at the end of the removal process, which makes it something of a non-starter in the first place. The possibility that legitimate files may have been infected or corrupted by the malware present on your PC, and also that security settings may have been lowered making your computer more liable to infection in the future, means that starting over is the easiest and most reliable solution to your problems.
You also need to be aware of the risk of identity theft if you have accessed bank accounts with this computer or shopped online. Keylogging software could have recorded details of these actions and a lack of an effective firewall means that there is nothing to stop this information being sent home. If this does apply to you, i'd monitor your accounts and perhaps consider getting credit/debit cards, passwords etc... changed - obviously not using this PC!
Should you want them, I can provide links to free software, both firewall and AV, that will help keep your PC malware-free in the future, but you shouldn't count on them to clean your machine as it is now.