Hi. My question is, if my computer has 8GB of memory then after using up some of the memory it depletes to lets say 7.5GB and the game I want says "System Requirements: Requires file system support for files up to 8 GB", will I still be able to run the game?
Ah, that 8GB is the space it needs on your hard drive. It does not need the same amount of space in RAM.
The amount of RAM it actually needs is a mere 2GB to run, and recommends 4GB to run well. Please bear in mind these RAM figures are total RAM installed in your system as it takes into account your Operating System, and other services, RAM usage. So your 8GB of RAM is more than plenty.