Apologies if this is totally the wrong track, but I just came across this link describing possible issues with Intel chipsets which mean that the SATA ports "Degrade over time".
Maybe worth checking if your computer might be affected?
Intel® 6 Series Chipset — Chipset circuit design issue identified
This one seemed a good explanation too; it's on the Acer site but looks like the issue affects more than just Acers so I think the description of the problem would be valid.
Intel Sandy Bridge issue, what you need to know
That problem was identified shortly after the chipset was released, and Intel did a recall of the chips. Nothing that has shipped in almost two years has this problem. Few systems were sold that had the problem, and most vendors had recalls to fix them. It's highly unlikely that you will run into this problem.
My laptop does that near exact same scenario with the intel 3000 graphics driver. Boots super fast for awhile then suddenly talks longer to start to paint the stop/login screen. If I don't reinstall the driver, eventually windows will take longer and longer and then forever to load that driver. Seems to be a conflict with something. It leaves 4101 event id's when happening. Display driver igfx stopped responding and has successfully recovered.
in my case, it doesnt take longer for me to start up windows... everything stays at the same speed but it freezes
on another note, this is the second day it has frozen. im on my third reboot. i have cleaned out the fans and stuff last night