[moved to Premiere Pro forum from faq]
You dont have to set it up; its a 64 bit app.
...although you can allocate the RAM amount for PPRO to use and what it leaves for other apps.
Nice touch Adobe. One of my hopes of the new 64-bit system was to be able to keep other apps up and running efficiently eg AEFX / PhotoShop simultaneously with PPRO.
Inside PP, you can tell it exactly how much to use, go into preferences and adjust it there.
I have a 64 bit, win 7 os, i7 860 quad processor, 8 g of ram, Ati Radeon hd 5450 video card with 1g ram.
Thank all of you so much for your prompt replies. I erroneously created a shortcut to 32bit cs5 and didn't know it. I was working in ps and noticed my system was using less than 4 g of ram. I freaked and wondered where my 7g+ ram went. It didn't dawn on me that I had misadvertantly fired up the 32b version until this am. It will in the future. All is well now. Love CS5. Sorry for the unecessary email.
Glad that you got it sorted and easily too!
Thanks for taking the time to respond, as it might well help others with 32-bit and 64-bit versions of software.