Hello, I own the Surface RT 32 GB Version. It says that I only have 184 MB free out of 26.4 GB on my memory, but I calculated all the room that my files take up (including music, videos, and documents), as well as all the room that my apps take up, and this amounts to about only 7 GB - so I should have 20 GB free on my surface. What is taking up all this memory, and how can I get rid of it? I doubt the pre-installed Microsoft Office can be taking up all or even the majority of that memory...