Hi Kelly -- welcome to PCHF
I can certainly empathize with your issue... but due to this Dell model's minimum specs-- I am afraid you WOULD be better off replacing the tower-- at minmum.
The issue with Dell's is that they not only have minimal performance for gaming ... but also just BARELY enough power to supply all their components. In order to change the
mobo in this PC --and get the graphics performance you want, you would have to change:
the motherboard-- and it would need 4 slots for
RAM = $120
add an AGP or PCI-express video card =$85
AND upgrade your 250 W power-supply to run all the new toys-- to at least 400W-- preferably 500 =$85
with all those new features-- onboard sound won't cut it.
+ 75 for a sound-card +80 for decent speakers
for $349 you could do this...
http://www.tigerdirect.com/applicati...958&CatId=1883
and save all the aggravation of trying to change all your hardware.
then sell your tower to get some back?