Windows 7 - Windows 7 hangs after startup and can't wake up after sleep

My PC hangs at startup. Nothing works, no mouse, no keyboard, everything just freezes! I turn on the PC in the morning and turn it off at night when i go to bed. It only freezes when I first turn it on in the morning. The only way to 'unfreeze' it is to do a hard reboot by pressing on the power button for awhile. The weird thing is, if i use to PC for a few hours then decide to reboot it, it works perfectly fine. Seems like it hangs after the PC has been off/idle for too long. This issue has been happening since October 2010. First it would hang maybe once a week (i ignored it thinking that its just a minor thing). Now i have the problem everyday!


Another problem I started having since a few days ago is that I can't wake my PC up from sleep after it has been sleeping for about 2hrs. I move the mouse and the fans will start running but there is no light at the power button to indicate that it is on and working. My screen is blank. I have to off the power switch and turn it back on. Then it will load everything for me like how i left it. Weird really.



The is no errors in my event logs. The only errors are from when I do the restart. There are no errors under system, nor under applications. (That's because I fixed all errors)


Hardware diagnostics did not find any hardware problem. That tool even did a memory test for me and found no errors.


Avast did not find any viruses.


I do a disk defrag and cleanup every week.


Windows is always updated.


I use a selective startup. The only Services running at startup are all Microsoft services and avast and Startup only runs windows live messenger and avast. PC still freezes.


I have called tech support as my PC is still under warranty. Tech support couldn't find anything wrong and recommended that I reformat the PC. I don't want to reformat my PC as I don't know if some of my licenses will still be valid after I reformat.
Note: I cannot open my case or my warranty is void.

Someone please help me solve this problem. Thank you.

Come on guys, 67 views and still noone can help?