Thank you for your input. I followed your advice, to no avail. I can sign off, but cannot restart, or turn off the computer. Pressing the "Panic" button, and restarting the computer does not help.
Running:
Windows 8 With Media center, on a Dell Studio 17 with a 1.5 Tb external HD, USB Mouse, remote touch screen monitor and wireless keyboard. Intel Core 2 Duo Processor T6400 @ 2 Ghz, with 4 GB ram. The printer (HP Color Laserjet 2600n) is networked. Drivers for it have been installed. Removing the peripherals and working directly from the touch pad, and built in keyboard did not remedy the problem. UAC has been turned all the way down, and Libraries have been disabled. I have not cleared the index.dat files. I don't know what effect that would have in Windows 8, and I don't want to break it before I start. There are 2 other computers on the network with 6 shared folders total. 1 is running Win 7, and the other is running (Viva Siempre!) XP Media center edition. I have not tried disabling the network. I am NOT, NOT, NOT, using Home Group. I have had no problem transferring files across the network, and don't think that's the problem. I just want to give as much information as possible, in case something small I mention strikes a chord.
I don't know if anyone else is having the same problem, but any help would be appreciated.
Thanks.