Looking to upgrade

[Zero4567]

Just got an old computer figured I'd upgrade parts for gaming can someone help me pick parts

Radeon HD 4200
DDR3 2gb ram
AMD Athlon 2 X4 640
Psu output 250w

 

[popatim]

We're going to need to know which motherbd you have. Thanks.

 

[Zero4567]

msi 785gm-p45

 

[hang-the-9]

If it's a standard tower case, double the RAM to 4GB at least, go to 8 with a 64 bit Windows setup if you can.
Upgrade power supply something like http://www.newegg.com/Product/Product.aspx?Item=N82E16817207036
And a 750 Ti, this will fit in a smaller case http://www.newegg.com/Product/Product.aspx?Item=N82E16814127836&cm_re=750_Ti-_-14-127-836-_-Product