I found this. Why don't you give it a try: spiritofaa 11-26-2009 at 05:05:12 AM
I have a T6412 Emachine and all I had to do to add a PCI Express graphics card is ...
using the onboard card, I went into Control Panel/System/Hardward/Device Manager... right clicked on the onboard video and selected disable.
The system asked if I was sure, I clicked yes, and then selected to reboot. After shut down but before it could restart I turned the computer off, installed the new card, plugged the monitor into it and it was finally detected.
Next I installed the new PCI cards software, and set up the display settings to my liking, and all is good now.