I was going to suggest downloading and installing the monitor drivers from
support.dell.com, but I see that the onboard video supports a maximum of 8
MB of memory (borrowed from system RAM). Yikes. That's not adequate to
support 1920X1200 pixels in 32 bit color.
I know of nothing that would prevent you from installing a PCI graphics
card. The 3100's mainboard only has two PCI slots, but I expect that both of
them would be usable. I suggest going to
www.newegg.com and trying a "power"
search (upper left side of the screen). You may not choose to buy from
Newegg, but this will still give you a good idea as regards what is
available. The lowliest cards there still have 64 MB of RAM. (I searched
only cards that had at least one DVI connector. I suggest going for that,
although it may not make a large difference in the real world.)
I looked whether ATI makes an All-in-wonder card that would give you a
graphics card plus TV capabilities in a single-slot design, but I only saw
AGP and PCI-E versions.
Good luck.
Return address scrambled. Replace nkbob with bobkn.