Stubborn Screen Saver Problem

[Bobby]

My screen saver has not worked since installing Vista on this PC, though I
have already tried the basics. Here is the scenario:
1- Am using corded Logitech keyboard and mouse (though I would like to put
my nice Logitech cordless back on eventually)
2- Vista Ultimate 32 on home built PC (quad-core, 4GB, nVidia 7950GT, SATA
HDDs)
3- already stopped and disabled hidserv.exe process
4- Tried to apply the HID User Interface patch, but the attempt failed in a
msg something like "This patch is not required by this system".
5- System is current with all patches.
6- Rebooted as part of normal use about weekly for the last 6 mos.
7- I don't see anything in the event view that looks related, but I may not
be the best guy for that.

Please help. If there is more information needed, please let me know.
B-

 

[Bobby]

A bit more info:
8- The monitors don't go into power save either (two are used on this
system). I assume this to mean that something is keeping the computer busy.
9- If I go to the windows logon screen via "switch user" or "logout", then
the monitor power does shutoff at the preset time interval. A screen saver
never activates.
10- A "preview" of the screen saver on the screen saver settings window
works just fine.