To start the computer using the last known good configuration
1. Print these instructions before continuing. They will not be available after you shut down your computer in step 2.
2. Click Start, click Shut Down, and then, in the drop-down list, click Shut down.
3. In the Shut Down Windows dialog box, click Restart, and then click OK.
4. When you see the message Please select the operating system to start, press F8.
5. Use the arrow keys to highlight Last Known Good Configuration, and then press ENTER.
6. If you have a dual-boot or multiple-boot system, choose the installation that you need to access using the arrow keys, and then press ENTER.
Choosing Last Known Good Configuration provides a way to recover from problems such as a newly added driver that may be incorrect for your hardware. It does not solve problems caused by corrupted or missing drivers or files.
When you choose Last Known Good Configuration, only the information in registry key HKLM\System\CurrentControlSet is restored. Any changes you have made in other registry keys remain.
NUM LOCK must be off before the arrow keys on the numeric keypad will function.