I own a Dell Dimension 2400, Pentium 4, 2.4 GHz & 256 RAM. For the past 30-45 days, I have experienced very slow response for all programs. I have Norton Internet Security with antivirus and spyware protection. I also use ad-aware, spybot, spy doctor and spy sweeper. I have gone online to Symantec to run the virus check that they offer. It took 10+ hours for that to run and the results were 2 files infected w/Adware.P2PNetworking & Adware.save now. I found the location of the infected files and removed them from the registry. They seem to be gone, but the CPU usage is still a constant 100%. My wife seems to think that all of this started about the same time that I set up the Dim2400 on a network in the house along with our Inspiron 6000. Any ideas to what could be making explorer.exe run aat 99% all of the time?
Mostly spyware but since you have all the application required to fight spyware, it is really strange!
I found the location of the infected files and removed them from the registry.
I may be wrong but it is not because you are manually deleting files that the spyware/virus is gone... It will always come back unless you delete the virus/spyware using some of the software you mentioned above or get pertinent info on the web about files to be removed (e.g. .dll, .exe).
I had the same problem with Opera - was quite surprise to see it was Opera and not IE. My opera folder was 2Gb!
Have also a look at your local settings. My 2cents.