Hello, I'll be quick coz I don't have much time on me.
I'm in Romania and I got 400Euro AKA 515 Dollars and I want to spend them on a new PC from scratch. except for RAM. I got 3GB and I don't need more. Thank you.

Sir, I will give some specs you might want to have depends on your budget. So since, your budget can only afford mid-gaming computer, then I will give an Amd Phenom II x4 processor and a GTS 250 graphics card also, you should buy a decent PSU like Gigabyte superb 500W to support your video card.. the rest is up to you sir.. and by the way, Phenom II is an AM3 Processor so you should buy any boards the comes up with AM3 Socket.. hope this helps.