Blank screen after installing new NVidia graphics card in my older Dell Dimension PC

I have an older Dell Dimension XPS T800R which has always performed well with no issues until yesterday when the original NVidia 32mb graphics card started having problems. I decided to purchase a replacement, the NVidia GeForce 7300 GT (AGP). I went through the installation process per the install manual. The new drivers installed successfully, but after rebooting the system I ended up with a blank screen. Upon rebooting I see the Dell banner, then the Windows XP banner with the status bar. After that the screen goes blank and within a few seconds I get the notification from my 24" Dell flat screen that it's going into power save mode.

I called the BFG Tech support line (the video card maker) and we went through a few options (making sure the old video device was diabled, etc.), even downloading an older driver for this video card, but end up with the same result, a blank screen when trying to boot up into windows.  The support person at BFG Tech said that I may need a BIOS update for my older Dell PC for this new video card to work properly. Does anyone here have any ideas on how to resolve this issue. Thanks, Tony