A:
Firstly I doubt the machine only supports 1400 x 1050, I'd suspect your monitor is your limit there. But in the event I am wrong, this card will allow you to run 1920 x 1080 (aka 1080p).
As for if you can use it, I don't see any reason why not since there is no power inputs on the card and the card would have to stick to PCI-x power consumption specs. That being the case, you should be fine. Although if not remember you can always return the card if it isn't compatible.