The Directory Restore Safe Mode (DSRM) administrator password is set up during the promotion process for the domain controller. To change this password you can use Microsoft NTDSUTIL tool.

Steps to reset DSRM password

• Click Start and Run.
  
• Type ntdsutil and click OK.
  
• Type the following command: set dsrm password.
  
• Type one of the following commands:

  1. reset password on server null – to change password on the local server.

  2. reset password on server <servername> – to channge password for another server (<servername> is the DNS name for the server)?

• At the DSRM command prompt, type: q.
  
• At the NTDSUTIL command prompt, type: q.