When I search for a file in Windows Explorer, as I click on the file, the screen goes black for a second, then the desktop setting changes from 1024 X 768 to 800 X 600. I have to change it back manually. It seems to be mostly when the file is an mpeg or wmv, and opens Windows Media Player. I have a Chaintech Zenith 9CJS motherboard (Intel 975P with serial ATA and dual-channel memory),with a Pentium 4 2.6 GHz Canterwood 800 FSB, and 512MB of DDR400 RAM, running Windows XP Home with Media Player 10, and Norton Systemworks 2005. The graphics card is a Gainward 7800 with Nvidia 5600 Ultra 256 MB. Any ideas?