Well I know that I want windows XP, not Vista..but which XP should I go with? What is the advantage of 64 bit? Does that have anything to do with having 4 cores? I just want to make sure I get the right one for my new system.

Also, where should I get it? I'm ordering all of my parts through Newegg.

Is there a difference between "retail" and getting it with a new system build?
Thanks for the replies in advance.
-Ryan

64bit has nothing to do with cores only with RAM size. With 64bit Windows you can use 4GB of RAM and above. Just get Windows XP Proffessional or Vista 64bit if you want to use more RAM (I haven't used XP 64bit but I have heard it has a bunch of problems).

I'm not in the US so I can't help you find where you can get it. But newegg have XP for sure. Just check the software/OS section.

Forget XP-64bit.
Lots of software/hardware compatibility issues.
Vendors simply did not write or test software for it because it came out so close to Vista which is replacing it.

Vista-64 is a reasonable choice.

there is absolutely no need for more than 2GB of RAM.\
If you choose XP then get SP/2

What compatibility issues? I have yet to find one (Using XP 64 right now) and I have both Vista Ultimate 64 and XP 64 Pro (old 16-bit software doesn't count, the platform was not made to support). If anything you have a more secure system, that can take advantage of more ram if needed, and in theory should perform better than any 32-Bit OS (Crysis devs have mentioned a 10-15% performance gain per core on 64-bit OS over 32-bit OS).

If I were to recommend someone an OS for gaming, it would be Vista 64 solely because of the future DX10 compatibility, since it's pretty pointless to buy ANOTHER OS down the road when one wants to use DX10. However, If said person prefers not to purchase Vista and wishes to get XP, then I would strongly recommend XP 64, after all, 32-Bit OS are for legacy support anyway.

1) Why does 16-bit software not count? You do realize that many 32-bit software packages have used 16-bit installers.

2) Drivers are not fully compatibie.

3) Services and related items do not always work.
There is a long list of items that simply does not work.

4) The larger available addressing space actually causes many programs to crash unless tested under XP-64.

I guess you don't read the MS Windows Forums or other places regarding all of the 64-bit issues. That is the primary reason why most PCs that ship with Vista stll ship with Vista-32.

Why should I read MS Forums? I haven't found a single issue. 16-bit is not supported at all on 64-bit OS, you can't call that an incompatibility issue when it was already announced that they would drop the support for it.

All the drivers I use and have seen people use are fully compatible. Even though they are usually not the best example for driver support, nvidia presently releases Vista 64 and XP 64 drivers on par with 32-bit OS drivers, for both Beta and WHQL.

If you are using software that is 5-6 years old there might be a compatibility issue, same with using that same software for vista, it might not work, simply because it's too old. But this is a non-issue for me, since all the apps I utilize are from 2007, and only very few of them are 2006.

I haven't heard or seen the larger addressing space causing problems any problems yet, but what I can say is this, I have had a pleasant experience as far as XP 64 and Vista 64 goes. If I had to pick one, it'd be XP 64 simply because I still have to learn more about Vista.