This post may be helpful to you, and certainly worth looking through. Tips on Troubleshooting Game Issues
If you use Steam for your games, the games themselves should be patched to the latest version already.
There are only a couple of exceptions, with certain games the use GFWL, that a patch may be needed.
However, GFWL will warn you and ask you to patch the game when you start it.
It may also be worth running the "Verify Intergrity of Game Cache" option for the particular game in Steam, just to be sure.
-- Im curious why you need 12GB of RAM though? This is really only helpful for High memory use, 64bit programs or if running multiple virtual machines.
Of course, if you do these things its quite understandable.
However, for gaming, it really does not help.
Most games are 32bit apps, and can only use a Maximum of 2GB system RAM anyway.
This is why many will say 4GB is the sweet spot for gaming, and up to 8GB if you want more.
If you have no specific need for that much RAM, it is possible it could hinder performance rather than help. Depending on the rest of the Hardware.
(Not saying this is the case, just a possibility)
More RAM slots full = More stress. And mixing/matching RAM could potentially cause some issues as well.