Hi Xiao,

Here is a "how to" I posted on my site. This will get you what you need. Good luck.

http://www.my80211.com/home/2009/12/27/recover-your-wlc-password.html

Also if u have WCS you can push a new account as an option. If you are on less then 5.1 your SOL unless you have WCS.

If you find this helpful please rate the post. Thanks

1. After the controller boots up, enter Restore-Password at the user prompt.
       Note: For security reasons, the text that you enter does not appear on the controller       console.

       2. At the Enter User Name prompt, enter a new user name.

       3. At the Enter Password prompt, enter a new password.

       4. At the Re-enter Password prompt, re-enter the new password.
       note: The controller validates and stores your entries in the database.

       5. When the User prompt reappears, enter your new username.

      6. When the Password prompt appears, enter your new password.