Windows 10 build 1607 sat in installing overnight. Frustrating to say the least. Clicked on settings and it said there were issues found. Clicked on that and it said I had some WMA, WMV, etc files that are "protected by an older rights management technology, which is not supported." I continued with Windows 10 Anniversary Update. I don't depend on WM_ files anyway. Here's MS details, a fix may be developed in coming months.