I upgraded my Vista Ultimate to Windows 7 Ultimate (RTM) and after that it doesn't wake up from sleep.
When I power it on it turns on but nothing happens, but if I press the reset button it boots and then wakes up, I mean, it doesn't reboot Win 7, it actually wakes up.
Anyone have any clue about such a weird behaviour?
It always worked fine on Vista. I have a GForce 8600 with the latest drivers.
Disconnect any and all unnecessary devices from your PC. Pare it down to the absolute minimum : unplug anything you can disconnect, turn off and unplug the computer from the mains for a few minutes, then reboot.
Look in your BIOS for the suspend ACPI options and try to switch modes among "S1 and S3", "S3" etc.
Ensure "Allow this device to wake computer" is checked in in "Device Manager/$device$/ Properties/Power Management", where $device$ stands for keyboard and mouse.
Its part Windows 7 and part driver issue (Vista drivers re-certified as Windows 7 when they should rewrite them for some devices). If you install windows vista then your sleep mode will work perfectly fine. On the other hand some other computers that uses Windows 7 (32 and 64) sleeps fine in S1 and S3 state like my Laptop Gateway. So it really depends, I recommend you want for a update patch or vendor updated Windows 7 drivers after you let them know of the situation.
I have been having the exact same problem with my AV Server/PVR machine (Intel MB) and spent almost a week (on & off) trying to solve it, so here is what worked for me...
Enter the BIOS and set power management to S1 - the Intel Bios warns about using S3 as some programs or device drivers do not work when set to S3 of higher.
In the BIOS - disable Wake up on LAN - I have been told that routers perform polling to see what is connected if they are in DHCP mode - this wakes the computer
I do not need to have LAN activity wake up this particular machine - so it is not an issue
seems my wireless router does not have this effect on the machine, but my wired router causes problems
Once I made these changes everything worked fine - even better than fine - since my ATSC tuner card from HAUPPAUGE wakes up the machine to record programs even from Hibernate mode, but then there is no keyboard wake-up - you gotta get out of the lazy-Boy and press the power button.
Sleep also works as required and allows for keyboard wake-up, but the fan stays on (not sure why)