It's a Dell Dimension 8250 w/ Windows XP if that helps. Unfortunately I have no idea about the dedicated GPU, "On board" type of graphics, PCI-Express slot, an AGP Slot, or if it doesn't even have a video expansion slot...
You have AGP, so you need an AGP video card.
Also, when the graphics card goes out, does it start using more memory as the PC got a good bit slower around the same time, although it may be a coincidence though.
Upon booting up, it said the system battery is low, press F1... Can I replace the sys battery also and how? Thanks for the help!
It could be a few things, your CMOS battery could be bad, or your motherboard could be failing, at least according to a quick google search.
Turn off your computer and unplug the power before doing this, also ground yourself before ever touching any computer part. During this procedure, ground yourself multiple times.
You should need a CR2032 battery, however make sure you open your computer and read the battery before purchasing one, as older motherboards used different sized batteries. Normally, the back of the battery (negative side) is facing you and it tells you the type and maker of the battery, you may not need to remove the battery to see the type.
To replace the battery is fairly simple, open your computer and look for a button cell battery, around the size of a Nickle. Take the battery out, remember the exact way that it went in, then put a new battery in the same way you took the former battery out.
Take a look at
This for more information about your computer.
"battery socket (BATTERY)" This is the battery that may need replacing.
Edit: your computer case opens in an unusual way, see below