I use Windows 10 Pro - 64 bits and I have the following problem: the welcome screen changes the expression "Welcome" to "Preparing Windows", then, after a long time, my desktop appears totally uncharacterized as if it were your first use, even without normal access to the Documents, Images, etc. folders. The problem returned almost always, so I formatted the HD and reinstalled Windows 10. After two weeks of normal use, to my surprise, the problem reappeared. Any solution?