Help upgrading my Dell Inspiron 560s

[theantidavis]

First off, yes, I know that this thing is a piece of junk and that I need to upgrade the PSU to get a decent graphics card, and even then, I would be bottlenecking with the CPU.

APPROXIMATE PURCHASE DATE: Sometime before July 9th

BUDGET RANGE: 300-400

USAGE FROM MOST TO LEAST IMPORTANT: Playing fairly old games on minimal settings with decent framerates (Garry's Mod and TF2 are the most important to me)

CURRENT GPU AND POWER SUPPLY: 250 Watt Power Supply, on board graphics

OTHER RELEVANT SYSTEM SPECS: Intel Celeron 450 2.2 GHz,, 2GB RAM, I for the life of me can't find out the Mobo

PREFERRED WEBSITE(S) FOR PARTS: Whatever has the parts cheapest

PARTS PREFERENCES: No preference

OVERCLOCKING: Not until I build my own build

MONITOR RESOLUTION: 1024x768

ADDITIONAL COMMENTS: I suppose I'm asking for a CPU, PSU, and Graphics card upgrade, which may be hard to do with the budget I have given. Also, I plan on making my own build later, so this is just temporary. Thanks in advance!

 

[bccorrupt]

Is it the slim tower or full size tower?

 

[theantidavis]

Is it the slim tower or full size tower?

I believe that it's the slim.

 

[bccorrupt]

That limits your choices by quite a bit, but luckily the games you want to play aren't very demanding. I'm not a fan of throwing good money after bad, so since your CPU is above the minimums for both games I'd stick with what you have. The newer Celerons aren't that bad with a $100 or less video card(which is what you're limited to anyway with it being low profile).

Power supply:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151090

Video card:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150682

Memory: (optional, but would help with other games and you could reuse it later on when you build your own)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820313072