When I boot up or change users, the screen goes goes black for about 5 minutes and then everything shows up and works fine. When I try to go to the Windows store, using the store tile, the screen changes to a dark blue color and nothing appears although my sign on was with the windows official msn email account. What do these black periods and blue periods mean? I sense the computer is searching for something?

I am using the Classic Shell also. I have the latest 8.1. I upgraded from the free evaluation 8.0 to 8.1 by purchasing the 8.1 download from Amazon. Twice the upgrade failed on my Verizon Home Fusion network so I took the computer to a friend across town who had a very fast Comcast connection and it worked the first time there.