Another idea would be to run msconfig from Start->Run, go to the Startup tab and see if anything suspicious is checked. Check the location of all items set to launch on startup.
You could also download process explorer from MS from this location:
Open process explorer then go to View->Select Columns and make sure Image Path is checked. Process explorer will show you everything that is running and the file location of each running process. You can sort by Path and check for anything running from suspicious locations. Anything running from temporary locations or files or folders with seemingly random characters are suspicious.
If you aren't sure about a process, upload it to VirusTotal.com. VirusTotal will scan the file with about 40 engines.
You can also quickly verify some files in process explorer by doing this:
right-click on the process->properties->Image Tab->Verify button - this will verify MS processes.
Hope this helps.