I have a Dell Inspiron N5050 that has been upgraded to windows 10. I doesnt work properly. (It suffers from the black screen on boot issue where you have to close and open the lid to get the display to show, plus the desktop continuous flicker/refreshing issue, plus the start menu will not show issue.) So I want to revert to WIndows 7. However I cant get to the revert menu item in the control panel as I cant get the start menu to work. I have also tried pressing windows + R key and typing "control panel". The control panel pops up and them instantly close again. I have tried running the command (the powershell window does seem to stay open): sfc /scannow and also I have rebooted + F8 key and done the Troubleshoot. Is there another way I can get windows 10 to recover back to windows 7? Unfortunately I dont have any recovery disks for the original OS.