I was running Windows7 on a Dell Inspiron Laptop. Was sent a link to upgrade to Windows 10. I clicked on this link and started to upgrade to Windows 10. Everything seemed to be working right. During the process there were message on screen saying stuff like it's just about done, it shouldn't be much longer, and it's taking a little longer than normal. After a while a screen with a window with light shining through it, looked like maybe a welcome screen, and my two desktop icons in the upper left corner, in the lower bar on bottom of screen is a small white window screen (assuming this is the start button, next to it is a message saying search internet. Over on the lower right corner looks like a wifi symbol and an on/off button. With my mouse pointer is the small blue round circle that I have some control over. The problem is the screen kept flashing on and off and I had no control of computer. Even if I pushed the ctrl alt delete keys I couldn't get control. I thought maybe I could revert back but even my right clicking on the desktop I can't open anything. After about a hour and a half I held down on off button and shut computer down. It flashes to fast to do anything. When I restart computer a window opens up with a rock formation and date on screen. If I don't do anything for about a minute the screen will go black, like maybe hibernation. If I click on the screen before the screen blacks out it takes me to a login screen. I've never had to login before. I just click on the login button without typing in a password and it takes me to the welcome screen ( the screen with the window with the light shining though it, the two icons on desktop in upper right corner, the start button and searching internet ?, and the wifi symbol and off button in lower right corner) and after about 30 seconds the screen starts blinking on and off. I don't even know how I can get into windows update and revert back on my own. I don't know how and/or if I can start in safe mode and revert back. Please help with fix and/or help. Thanks!