so I have 8GB of ram but half of it is used up so I only have about 4.2 GB of available ram would this affect the performance of my games much? If so is there a way to lessen the amount that is being taken up? Thanks in advance
Unused RAM is wasted RAM. Part of that usage is probably cache that is actually available if needed Performance will not degrade unless you use almost or all of the RAM and page file thrashing occurs. That said, no you are not using enough to degrade performance.
Windows will use RAM effectively. If it has enough, it will use more but if another application needs more RAM it will most likely cut its usage. You're probably fine as far as performance, if you see a 100% memory usage try to close some tasks
Windows caches frequently accessed data in free RAM. The more RAM you have, the more Windows will cache in it, to an extent. That cached RAM is still available for processes to use if free RAM runs low, and thus has no negative impact on performance. To give you an idea when I upgraded from 8 to 16 GB of RAM, Windows started using quite a bit more RAM.