monitor resolution won't change

Hello. I have a problem with my Dell 2350 with XP home. I can't seem to change the screen resolution from 1024x768. I have switched up the resolution many time in the past, but suddenly when I try to change it, the screen goes black like it should, but when it comes back, its still at 1024x768. This was ok with my old 17" crt, but I just upgraded to a Acer X231h lcd which is widescreen, so I want set it to 1920x1080, which is the native res., or at least a widecreen setting, so everythings not stretched. Also I can't change it from 32bit to 16bit color.

I tried reinstalling the graphics driver (intel 82845G) with no change. The only thing that I can think of that was out of the ordinary was trying to fix a Viewsonic lcd with a bad inverter board (I think...) so I had that hooked up for a little while, and was able to change the resolution with that. Then when I hooked my old crt back up, resolution wouldn't change anymore.
Any ideas would be awesome!