Video problems with FS 2004

I've been having a problem with this software. A couple of months ago I changed video cards. I am now using a BFG GeForce 7800 GS AGP card with 256 MB of memory. I've had to uninstall FS 2004 and reinstall FS 2004 more than a few times because I have a lot of add ons and I think some of them cause conflicts with either the video card or Windows XP professional Service pack 2 which is the operating system on my computer. I have installed FS 2004 again and when I start the program this time first the screen goes black and then everything on the desktop looks distorted and out of focus. Colors look faded. When I go into settings and then display there is no video card selection. It's empty. If I let the program run and go to create a flight the program does one of two things it will boot up in it's fuzzy picture state or the program will go away all together. I've installed the latest drivers from NVidia so I don't think that's the problem. Any thoughts on what could be causing this? This does not happen to any other program on my computer. Just FS 2004. Thanks for any help I can get. I have a Dell Dimension XPS purchased in 2002 with 2 GB of memory. Mike