Second monitor not detected

[monicole]

I have a Dell Vostro/200 with ATI Radeon HD 2400 Pro Graphics Card. My primary LCD monitor is hooked to a DVI Port that has a splitter. It works fine. When I hooked up the second monitor (same size same type) it was not detected even though I set input to DVI. I'm using Vista Business 32 as my OS. I tested the second monitor by hooking it to the original DVI, it works fine but the primary will not work on the alternate DVI connection. This monitor also works fine with my Dell Notebook running Windows 7 64 and will do either duplicate image or run simultaneously with notebook. Haven't figured out how to extend image between two different size displays. My question is, Is this a hardware problem with the DVI splitter? or can some setting in my Vista OS be causing the problem. I'm about ready to do a clean install of my Vista OS?
Thanks for helping

 

[Patonb]

I think it is the splitter. I'v never used a splitter like that.

If it was me, I would run 1 mnitor on th dvi, and the other on the vga slot. This is how the manual says to do it, as well how i use to do it with my 8800gt