Windows NT can be very temperamental sometimes are you add new software or install a new driver. The option allows you the create a Windows NT alternative to the Windows 9x Safe Mode. In this mode extra checks are performed and not all third party drivers are loaded.

Change the attributes for BOOT.INI so it is not 'Read Only', BOOT.INI is found in the root directory of the first partition. And open the file using Notepad or another text editor (not Microsoft Word or any word processor).

Listed under the [operating systems] section are all the OS's the NT boot loader can launch. To create a new safe mode entry copy one of the existing NT entries and paste it on a new line.

At the end of the new entry add '/sos' (without the quotation marks), change the description of the entry to reflect that it is safe mode. Additional adding '/basevideo' will launch NT with the default VGA driver.

The new entry should look similar to:
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Workstation Version 4.00 [Safe Mode]" /sos /basevideo

Changes will take place on the next reboot.

Disclaimer: Modifying the registry can cause serious problems that may require you to reinstall your operating system. We cannot guarantee that problems resulting from modifications to the registry can be solved. Use the information provided at your own risk.