Windows does not start successfully or repeatedly displays a blue screen

• When you turn on the computer, press the F8 key on your keyboard repeatedly until you get a Windows startup menu (like the one in the image above). Choose to start Windows in 'Safe Mode'. If Windows boots up and you can login, restart Windows and let it boot as normal which may resolve the problem.
• When you turn on the computer, press the F8 key on your keyboard repeatedly until you get a Windows startup menu (like the one in the image above). Choose 'Last Known Good Configuration', which will try and load Windows with the settings that last worked successfully.
• Do a System Restore to a previous working state (see below).