Forgot the admin password to the following switches 3824, 3812, 4250T.

Does anyone know any backdoor ways or how to reset the unit back to factory. My line manager has forgot the passwords

Here you go

1.Access the Command Line Interface and enter the user name "recover" and password "recover" to place your unit in password recovery mode. The unit will remain in password recovery mode for a maximum of 30 seconds, before it returns to the CLI login prompt.

2. During the 30 seconds, perform a hard reset on the unit while the it is still in password recovery mode by switching it off, waiting a few seconds, and switching it on again.

3. When the unit has rebooted following the hard reset enter a new password for the "admin" user account.

4. Enter enable to leave password recovery enabled, or enter disable to turn it off. You are now logged in as the default "admin" user.

Cheers