I need help in building (upgrading) my PC for gaming my budget is around $500?

Well, If you are really tight on budget then I can tell you exact what you need to hear. Well first thing is your smps is useless here, sell that off on ebay. You haven't mentioned here what type your ram is ddr2 or ddr3?

We can use your RAM, your HDD, fans for cooling, grab HD6670 1 GB GDDR5 $95 as your GFX card. MB DH55TC $90, Intel core i3 540 $105 and and corsair CX600 v2 $45 I think your current HDD 250 GB is enough for decent gaming anyway HDD is most expensive these days and will be out of your budget, and this Motherbord DH55TC supports only DDR3 ram, so either you buy RAM sticks which are DDR3 or grab this AMD Phenom II X6 for $100 with Motherboard ASUS M4A89GTD for $85. So remember if you have DDR3 RAM go for Intel and if you have DDR2 got for AMD cpu with asus MB.

You won't be needing more ram as you have enough for regular gaming. Hope this helps!

Rahul can you help me out through email directly... on pc build.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.