Upgrading MoBo/CPU on Windows 7

Dinesh said:

If you are already planning to get DDR3, i would suggest you to go for 8 GB instead of 4. You're already spending a good amount on the upgrade. So why getting the same 4 GB.

But with 32-bit, doesn't it only use a certain amount of RAM? (I heart it was 3.5 or 4gb)

I would expect a DDR3 user to want to utilize triple channel RAM and thus get 6GB of RAM (3 x 2GB).

And yes, 32-bit OS's have a 4GB limit. With other devices and the way the memory is addressed, you typically have access to about 3.2GB worth of that RAM.

I would definetely go for the 64-bit if there was a way for me to acquire some kind of download of the 64bit RC and an activation key before tomorrow mid-day, which is when I need to have this PC built and ready.
Would anyone perhaps by any chance have a download link that they could provide, and an activation key? This would be greatly appreciated.