Based on the context of the question, to clear a password in server 2012 r2 with boot disk when repair command prompt requires password involves booting the server.
To clear a password in Windows Server 2012 R2 when the repair command prompt requires a password, you can follow these steps:
1. Boot your server using a bootable disk or USB drive that contains a password reset tool.
2. Once you have booted from the disk or USB drive, follow the instructions provided by the password reset tool to access the Windows installation on your server.
3. Locate the Windows installation directory. Typically, it is located in the "C: \Windows folder."
4. Look for the "System 32" folder within the Windows directory and find the "sethc. exe" file. Rename this file to something else, such as "sethc. exe. bak"
5. Now, find the "cmd. exe" file in the same "System 32" folder and make a copy of it. Rename the copied file to "sethc. exe."
6. Restart your server and let it boot normally from the hard drive.
7. Once you reach the login screen, press the "Shift" key five times in quick succession. This will open a command prompt with administrative privileges.
8. In the command prompt, type the following command to reset the password for the desired user account:
net user (username) (newpassword)
Replace (username) with the username of the account for which you want to reset the password, and (newpassword) with the new password you want to set.
9. After successfully resetting the password, close the command prompt and log in to your server using the new password.
10. Finally, don't forget to restore the original "sethc. exe" file by renaming "sethc. exe. bak" back to "sethc. exe" in the "System 32" folder.