crash - Windows 7 Freezes (No BSOD)

It looks like Windows 7 (x64) froze on me at 8:30AM this morning (I found it like this almost 12 hours later). No blue screen, just frozen. It looks like the screen was a darker than normal, almost as if it froze perhaps before the UAC screen was going to appear (no idea why it would, I wasn't using the computer) or maybe it was going to go into screen saver mode.

This happened about a week ago as well.

I'm currently looking to update all of my drivers in case that's the culprit.

Last event log entry was at 8:28:47AM : "The Computer Browser service entered the stopped state." Looking at the log it looks like the Computer Browser starts roughly every 2-3 minutes, so I suppose that can be a culprit as well.

Any idea on what I can do to find out what's causing the issue? Unfortunately no core dump since a BSOD did not occur. Its really frustrating when you're left with so few clues.

---

UPDATE (JAN 16 2010)

After a couple of months of not having issues, my computer started freezing again. This time however, I was able to replicate the problem.

Using FireFox, on Twitter using PowerTweet, if I scroll up and down multiple times (or even use page up/down keys) I am able to get Windows 7 to freeze (again not BSOD, just frozen... to the point where even caps lock or num lock don't light up on keyboard).

I'm not sure if the real problem is FF or if it just more easily manifests itself using FF. I'm also not sure if the problem is really PowerTweet, or if its the fact that PT expands multiple Flash Videos (maybe the problem is Flash?).

Either way, the most I'd expect is FF to crash, not the entire computer. What do you guys think:

1. Software problem (FF or Flash)


2. Video card problem (hardware or driver)


3. Mouse driver problem (because it happens on scroll... although the bug did manifest itself through page down key so I doubt it)


4. Windows 7 bug

Further info: I've tried to update as many drivers as I could... video card, chipset, audio, etc. So if its a driver issue, then unfortunately its probably not fixed yet.