How to start Windows to safe mode :

• If the computer is running, shut down Windows, and then turn off the power
• Wait 30 seconds, and then turn the computer on.
• Start tapping the F8 key. The Windows Advanced Options Menu appears. If you begin tapping the F8 key too soon, some computers display a "keyboard error" message. To resolve this, restart the computer and try again.
• Ensure that the Safe mode option is selected.
• Press Enter. The computer then begins to start in Safe mode.
• When you are finished with all troubleshooting, close all programs and restart the computer as you normally would