Lets check that question out step by step.
I want to use linux for gaming.Which version of linux should i use(64bit preferred).I wanna play all games such as COD4,Crysis warhead and upcoming Hell's Highway.And is there an alternative for hamachi?
Yes Linux can be used to some success for gaming as well. I have personally run CoD4 , EQ , Chessmaster and UrT on it. The question is how much of performance are you looking forward to. if you want every single frame you can juice out , then stay away from Linux. On the contrary if you just are looking for an experiment to see what its like and to fool around with Linux then yes go ahead and try it out. Usually most popular games work on Wine but there are exceptions.
As for Hamachi I believe they have a Linux version also available ? Or at least on their website they do.
I just have a lot of harddrive space to spare.
Why not keep Windows for gaming and then put Linux in their for giggles and give it a whirl
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Will i be able to browse the internet using EVDO considering 64 bit drivers are unavailable.
I believe I have helped someone here on setting EVDO using the threads here in the forum. Just check out the Ubuntu threads I believe he had Ubuntu as his distro. Also I would recommend starting off with the 32 bit version rather than 64.
I want A GUI based free distro.
Many people still believe that Linux is some kind of command line terminal which geeks only use. The truth is far from that. Most Linux versions come with a GUI . You could try out one of the user friendly distros like Ubuntu , Mint, Mandriva etc.
Also you might want to check out tools like Cedega and Crossover Office/Games.