Windows Vista [Task Scheduler reporting 4 corrupt files]

Hi; I'm running vista HP w/sp2 and all updates.
When i run the task scheduler it comes back with 4 corrupt files.
1. 687a8f8a-777a-4c89-8b7f-8f295b19c004.
2. 318c32fc-9dd1-40dc-8b7f-4c9f1121ede.
3. 2f2c5506-730c-43d5-9ba3-b2a1abe76d4e.
4. 32CB0898-ED1F-417F-AB03-6992ED9532E4.
i Was going to delete and reinstall them, but am unable to determine what the names really are. I think item #4 is "sys diag" or "PC-Doctor ". The rest are unknown.
I searched the registry and find no instances of any of them.
OS takes 2.5 to 3.6 min to open (Quite Slow), I've shut down all the services and processes I can to speed it up and I am thinking the task manager is waisting time trying to load or reload these corrupt files. What say?
Appreciate any help!

 

Hi Admin;
I have run MalwareBytes. Superantispy, Windows defender, Avast, all show no signs of an infection.
Also ran MBRCheck and SystemLook, Forgot which one will not run, get err msg "script missing" or something to that effect.
I also run CCleaner and the registry cleaner. from time to time.
I do not open any attachment on email unless I KNOW the source, no brousing in dangerous areas although I do some research on medical and other IT sites, If I'm not sure I Use a sandbox.
Any programs I download come thru "CNET" which I have never had a problem to my knowledge.
I will get into virus forum and run the suggested tests and submit there.
Thank You for your time!

 

When I launch Task Scheduler, I get the 4 references as mentioned.
I searched the registry for each of the 4 problems. No results. Also scanned Windows System Folder, No rusults.
I have two diag programs that no longer run, the HP "sys diag" no longer will run. hangs.
And PC-Doctor will only run cpu & memory tests, no longer will scan any hardware like it used to.
I was going to delete PC-Doc and reinstall but the oem restore file does not contain the prog.
Admin suggested virus or malware, see his post and my answer.
Thanks Steve.

 

Sorry guys I thought the reply window would insert the message I was replying to, but I see it does not do this,
Thanks Admin & Steve.