In answer to your questions:
1) The problem as far as I have been able to determine is only when playing WOW - If you're familiar with the game I can play for about an hour, give or take, and then I have to exit and reboot the pc or the problem I described will occur. The new area Blizzard added, Sunwell, is horrible. The pc lasts for about 15 minutes to a half hour there.
2) Once I take it too far and the video goes out in the game the desktop will not correct itself. I have to restart the pc.
3) The display properties remain unchanged.
4) Unfortunately, according to Nvidia, I have the latest and best video card that my pc will handle. I also contacted Compaq/HP and have the most recent bios and motherboard chipset that is available.
5) Here is what I'm running (I know, I know - don't laugh. You're pc's will be old and decrepit some day too
Operating System Microsoft Windows XP Home
OS Service Pack Service Pack 2
DirectX 4.09.00.0904 (DirectX 9.0c)
CPU Type AMD Athlon XP, 1458 MHz
System Memory 1024 MB (DDR SDRAM)
Video Adapter NVIDIA GeForce FX 5500 (256 MB)
3D Accelerator nVIDIA GeForce FX 5500
Thanks for the responses.