I'm running the lastest version of Parallels Desktop on my iMac 64x with 10.5.8. I have 2 GB of RAM, but when I go into Parallel's desktop, it says I only have 1,432 MB (just over a gig) and Windows 7 Ultimate (64 bit) only wants to use/sees 768 MB. Which makes it impossible for gaming. This picture shows Windows 7 is only recognizing 768 MB of my RAM. http://imgur.com/DiWEK.png This picture shows Parallels Desktop only seeing just over a gig of my RAM. http://imgur.com/RokDT.png
I’m sorry for the troubles you’re having. To solve the problem as quickly as possible I recommend submitting a support ticket with the Parallels team http://www.parallels.com/support/.