<p>Obviously, that's 64-bit windows.</p>

<p>Also, what's the maximum amount of memory a single 64-bit process can use?
I was kind of counting on using it all... 
(Yes, I know what I'm doing, please don't tell me that if I need that much RAM i must be doing something wrong)</p>

<p>Also, is this the same for a .Net 2.0 process? Or is there a lower limit for .Net?</p>

Something we found out recently: with MySQL running on Win32, you can only use up to 2GB per process. On Win64, the memory is not managed as well and a single MySQL instance will run your memory into the ground. Ours used up all 16GB we have. So regarding how much memory 1 64-bit process can use: the answer is however much the OS allows.