Please Help Me! My Laptop Is Going Bonkers! It’s Soo Slow & Bizarre Rapid-fire Error Popups Galore!?

Ok. Got my laptop back from factory repairs (system restore by HP). This is the pop that I got earlier, I got like 20-30, like 3 per second: http://tinypic.com/r/4k7ddf/5
Firefox 9.0 randomly crashes. (So did 3.6.25 etc..)
I uploaded the bios and drivers from HP site but when I clicked to run it, it said it could not be installed. I clicked “Try again” it said it was already on my machine.
I have had a Java update. Am I supposed to manually delete the old one? Where do I find it (if yes)??
My WMP will not play videos: says an audio codec is missing but doesn’t tell me which. I DL’d the CCCP pack which told me to DL another one from MS but that did not solve anything. Still can’t watch vids. But it will play my music files…hmm?!
I had Norton & deleted that, left McAfee, still picked up the Google Redirect virus. Neither of those AV, nor AVG or Malwarebytes nor Kapersky rootkiller (TSSKiller) can find it. :-/
My laptop starts very sloooooooooooooooooooow. After less than an hour on Firefox all the tabs get stuck, takes 45 secs to switch pages, click links and eventually it crashes.
Any help that solves my problem you can offer? Will be very grateful, thanks!!!