I think that the question sounds clear, but for further explanation:

Suppose we have Windows 7 x64 PC with 8GB of RAM installed on it; (64bit OS with 32bit process is my intention)

Question 1: how much memory can a 64bit process use in this environment?

Question 2: how much memory can a 32bit process use in this environment?

Question 3: If a 32bit process can only use 2GB of RAM in this environment,(even if it is LARGE ADDRESS SPACE AWARE: 3gb), however most games are 32bit;, so does this mean that: Although we have 8gb of RAM installed, that a game for example can only use 2-3gb of RAM at any given time?