Vista - Hard drive seeks very fast while Screen saver active

I have a problem with a either spyware or virus that I can't seem to get rid
of. My hard is seeking Very very fast whenever the Screen saver is going. If
I were to leave it that way it would probably burn up the hard drive. Has
anyone had this problem and found a solution? I've ran both avg and adaware
and not found a virus or spyware. When I run task manager nothing shows up
yet I can hear the hard drive working very hard.

if you think it's a virus, download avast: avast! antivirus software - computer virus, worm and Trojan protection by ALWIL Software
they offer a free home license. you can register really quickly via email, but shouldn't need to for a one-time scan.
Once you install it, it will probably ask you if you would like to run a 'boot time scan'. tell it no and restart. when you've restarted, right click the little spinning 'a' icon in the lower-right corner system tray (the avast icon), go to updating->program update. avast will update itself.
now that we know avast is up to date, it's time to schedule the boot time scan. right-click the avast icon again and click 'start avast antivirus'. it will scan the memory before officially starting. if it doesn't catch the virus in the memory scan (which it may), it will proceed to the normal window. there's a little menu button in the upper left, click it, click 'schedule boot-time scan'
check the 'scan archive files' box
you can set the advanced options however you want, but be careful about always delete or always move--if the virus is attached to an OS file this could cause damage.
click 'schedule', restart. avast will now scan every file on your computer from within an isolated utility, allowing you to scan system files, etc.
THIS TAKES A LONG TIME!! if your hard drive is really big or really full, we're talking several hours. but if you've got a virus, it's worth it!
After the boot time scan, if avast hasn't found anything, then I can tell you with 99% accuracy that it's not a virus. while avg is good, i've found it will often miss virii that avast will not.

if avast comes up with nothing, most likely it's not a virus, in which case good luck, you're on your own.

There are three items which operate "discretely" (?) in Vista. Try disabling them temporarily to see if that is the only problem.
1. Defrag. Check if it has defragged completely since installation, and what schedule it is on. Once it has done the initial defrag, you will not notice it as it runs during periods of inactivity. You will find it in All Programs.
2. & 3.Open (Type in RUN) Services.msc. Disable, for the test, Windows Search (That is the indexing, which I think is the culprit) and Superfetch.
Log off and on and wait for the screen saver and see if the problem has gone away.
If you feel you need these two latter services, re-enable them one by one. I am told that the indexing "thrashing" improves over use, but I did not find that to be so.