Computer freezes after sleep?

Hello. When I put my computer to sleep, it sometimes (about 1 in 3 sleeps) just freezes instead of shutting down the fans and everything. I can't turn it back on, so the only way to shut it down is to either hold the power key or reset the computer. I've tried everything to fix this. There are no error logs in event viewer, there is no dump file. There is no AV program, no firewall or anything that might stay resident.
Windows 7 Ultimate SP1 x64, upgraded from RTM build 16385.

Read through this Tutorial to see if it is of any help to you.


Power Options and Sleep Mode Problems - Vista Forums

Thanks. Well, I went through everything.
-all drivers and BIOS are up to date.
-Windows simply can't go to sleep properly, not that it can't wake up. Rules out 3/4 of the tutorial.
-Power state on BIOS is set to S3.

I did some minor adjustments on power settings, which I highly doubt that will affect anything.
The only thing that I haven't tried is to reset CMOS defaults, which I believe that is kinda pointless.
The computer is like the only thing gets shut down is monitor, keyboard and mouse. Hard drive is working as usual, fans are spinning, but the power key does nothing.

Here's the exact problem as mine:
https://www.sevenforums.com/crashes-d...tin-sleep.html

Check this article out...

Some Windows 7 customers reported issues with putting their computers into Sleep Mode after they installed Service Pack 1 RTM.

A member of the Microsoft Product Quality Team has confirmed the problems and offered a bit of insight into what’s causing them, as well as some advice on what users can do to fix the glitch.

“Prior to the SP1 installation the system properly went into sleep mode and properly woke up. But, after installing Windows 7 SP1 you may not be able to properly put the system into sleep mode,” the Microsoft Product Quality Team representative said.

“You have to press the power button to force the system restart, and it will show an error that the machine was not shut down properly.”

Windows 7 Sleep Mode Issues After SP1 Is Deployed - Softpedia

Actually, after some research, I found out that the freeze occurs after the computer has been working for several hours (at least 5-6). When it works for less than few hours, it doesn't crash.
This happens even before I applied SP1. Could it be hardware-related issue?

Is your computer under Warranty?

No, but I can fix most of the problems which are not hardware-related by myself.

Your persistence noticed.
Good luck.

Are you being sarcastic? I'm looking for ideas what could be wrong.

Not at all....

It surprises me though that no one else has tried to assist you.