I noticed that one of my VMs (on Hyper-V 2012) was using a lot of RAM. Strangely, there was no application which was using that much RAM. It was using 14.2/16 GB RAM. At that time task manager showed this: And this in the details tab: Notice that Oracle was using only 1.8GB and that was the highest user. Even if I total everything, it still was nowhere near 14 GB used. What was using all that RAM?