To fix black screen of death in Windows 7/ 8, try the following steps,
Press Clt + Alt + Del
Type cmd and press Enter
Type cd c:/windows and Press Enter
Type dir explorer.exe /s /p and Press Enter
Copy the last diretory (right click in cmd ,click “mark”,and click “enter” to copy)
Paste (Right click in cmd and click “Paste” and Press Enter
Type explorer.exe and Press Enter
And here goes the Windows