I have been working on a Windows 7 issue for over 5 months with no success.  Sometime around New Years my computer stopped going into standby, screen saver, or to turn off display.  Even with Balanced Power settings selected, screen saver at 5 minutes, display off at 10 minutes and standby at 30 minutes I could come back to the computer hours later and the desktop would always be shining bright. 

Thanks to the Internet Adviser and pure dumb luck I have resolved the problem, no answer, but I do know what causes the miss-operation.  My Windows 7 was on, I was planning on calling into the Adviser during the June 11 second hour, and I was arranging my question so it was smaller and covered most of my software efforts, 

I do system backups on a monthly basis, so I was able to try restoring previous backups, at least 4 months back, tried various msconfig disables, task manager "End Processes", and not opening any programs right after a fresh boot.  I even installed windows 7 on a spare hard drive, adding only AVG, Zone Alarm, Malwarebytes, Firefox, and windows patches/updates.  Still no automatic standby.

Internet Adviser.  (?) Nothing, except that I was listening and not computing when out of the blue my screen turned off.  Only time in months.  My wireless mouse's USB adapter had not been plugged in, the only thing different in this boot-up.  Could it have something to do with the wireless mouse?  Subsequent tests show that any wireless mouse whether Microsoft's or other brand is activated Windows 7 will not go into screen saver, display off, or standby on its own.  Never have seen this problem even with my Vista laptop.  Any thoughts??                   Charles

I mention the BIOS first as that was the most difficult test to do.  Even though my Mother Board has a generous 4 seconds time to display the "Press Delete to enter BIOS" I have been unable to get the computer to co-operate.  Neither keyboard delete keys pressed individually, alternatively, or frankly rapid tapping would bring up the BIOS. 

The mother board has 4 USB ports on the board and plugs for 2 USB ports on the face of the computer.  To the MB's 4 ports I have an extrernal hard drive, a printer, a casette to MP3 device and a Targus 4 port USB expander that I keep on the desk. 

I use the Targus to plug in a keyboard wireless adaptor, the wireless mouse, and whatever jump drives I want to access.  On a hunch (only a hunch) I moved the keyboard's USB adaptor to one of the front panel USB ports.  Into the BIOS immediately.  (Uh ??)  In a later testing I tried the wireless mouse adaptor in the other front panel UsB port but plugged in, the computer ramained active and would only go into screen saver etc after being unplugged. 

Getting back to checking the BIOS, yes there are some USB settings "Enable/Disable" and I set all at the oposite of what they were set for, and later left them all "Enabled".  From BIOS I went to the power management suggestion. Control Panel > Mouse  > Hardware > Properties > HID-Complient mouse properties >  Power Management > Allow the device to wake the computer.  I unchecked the box as per your suggestion. 

No effect here either.  But there is a bottom line here:  A hard wired mouse works OK so the problem is strickly with the wireless mice.  The hard wired mouse I am using has the USB connector so that rules out the possibility of USB vs PS2.  I tried the hard wired mouse some weeks ago and will continue with that approach.          Chack