Alot of spyware doesn't work too well, my secret ace is malware bytes, brilliant free app and if its a spyware thing, that'll get em.
Usual things, do a disk clean up, disk defrag, run msconfig (Happy now?
) and disable any programs you don't need in start up (careful what you turn off here).
As far as software goes, hope that helps. It seems to do the business on most slow PCs we deal with. Hardware seems fine so that won't be your bottleneck. Now overclock that PC!