That's a BTX format case; I wouldn't put any more into it except for maybe a better video card that will work with your dell ps. It's probably worth more if you sell it intact on ebay. Atx boards won't fit without taking a dremel tool to it; better to buy a new case, ps, etc and start over. Dell had a terrific deal on the inspiron 660 desktop system a few days ago with an i5 cpu, but that's over. You might see some more deals in mid January with Dell and HP on their websites.