I have a Surface Pro 4 i7 / 16GB running Windows 10 Version 1607, 14393.953. Trying to use Windows Explorer with Preview pane leads to some bizzare results.
At times, MS office files (Word, Excel, Power point) as well as PDF files simply will not preview ("This file can not be previewed")
Sometimes, those same files will show in a small window within the preview pane, with huge scroll bars. Even the mouse pointer gets larger when I mouse over that area of the screen.
The worst is similar to the above situation, but if the file type happens to be excel, it will often be blank for minutes, as my fan shifts into high gear. Excel shows taking upwards of 30% of the CPU for an extended period of time. In these cases, if there is an excel window already open, the size of that window, and fonts / elements within it, can be changed randomly. The CPU utilization / Excel task remains even after all Excel windows are closed, as well as the Explorer window. I need to use Task Manager to End Task.