Dell 4600 Series

I'm not sure, you'd have to check whether your motherboard can suit any upgrades because that Pentium 4 would be a big bottleneck if you plan to upgrade the graphics card for gaming. Adding more RAM might help, although if your budget is big enough, it may be better to make a new system.

I agree a RAM upgrade is most likely the only thing worth while that isn't a new build.

graphics wise I have a 128 MB GeForce MX 440 card in there. Don't really have the budget to get a new computer unless its rent to own but not really enthused about those prices. Have an 8 month old baby in the household so most of the finances are tied up there so can't really afford to put maybe 50-$100 bucks into the computer.

A CPU upgrade really isn't cost effective and your options would be very limited anyway for a minimal change in performance. Best bet is to max the RAM for your system. You could also add an updated AGP video card, but once again, it will be questionable in terms of cost for performance gained.

My recommendation. Start squirreling away money to buy a new system and live with what you have until then. If you do anything with this, add memory.