To use a Safe Boot option, follow these steps:
1. Restart your computer and start pressing the F8 key on your keyboard. On a computer that is configured for booting to multiple operating systems, you can press the F8 key when the Boot Menu appears.
2. Select the Safe Mode option when the Windows Advanced Options menu appears, and then press ENTER.
3. When the Boot menu appears again, and the words "Safe Mode" appear in blue at the bottom, select the operating system installation that you want to start, and then press ENTER.
Please visit this page if you need some additional info: http://support.microsoft.com/kb/315222
If it doesn’t work (there could be some system issues or virus actions), please execute the following script in the AVZ utility:
It will automatically restart your system. Please try booting in the safe mode one more time.