Upgrading my motherboard, graphics card, processor

hello all,

So in explaining the title of my post I'd like to change my mother, my graphics card and my processor but I do not know what to choose. At the moment I have a rather old pc.

Thank you in advance for your help.

If you want more details ask me.

Hi

What type of application you would like to tour on your new configuration? Games, office ...?
Has strips you of RAM? if so what type?

my budget is Rs 20000, I have DDR2 (two 2GB)

I used my PC primarily for online games (WoW, CS ...) and PC games (GTA4, Battlefield 2142 and other recent games ...) and for playing videos.

I try not to have a powerful super computer just enough for my PC is fast and does not RAM when I play.

A you have a preference for the processor between AMD and Intel?

Otherwise I propose:
Motherboard
processor
ATI graphics card Radeon HD 3870 - 512MB DDR3