I have a vostro 400 and I had a nvidia geforce 9400 gt and all was good. Today I got a nvidia geforce gt 240 from a friend and I replaced my old card with this new one and all I got was a blank screen. From what I can tell the computer doesn't even see the graphic's card. I even tried to install the latest driver for it and it said that there was no compatible device for it to work with.