Thanks for the quick responce. Fortunately I have created a local user priv 15 on wlc. I disconnected WLC from the netwrok. Then I could be able to login through the local user.

I have one question if i dont have fergot the local user id and password, in that case will my configuration will lost during the recovery process?

Thanks for ur help.

That link is for a 4400 router. If you clear the config from the boot, then you will loose all your configuration and will have to configure the wlc fro the startup wizard. Here is a Q&A fro the WiSM, which is the same for the 4400's:

How can I reset the WiSM to factory default settings?

A. Complete these steps to reset the WiSM controller to factory defaults:

1.Enter reset system at the WiSM controller CLI.

2.At the prompt that asks whether you need to save changes to the configuration, enter Y or N. The unit reboots.

3.When you are prompted for a username, enter recover-config to restore the factory default configuration. The Cisco WLAN controller reboots and displays this message:

Welcome to the Cisco WLAN Solution Wizard

Configuration Tool4.The WiSM is now reset to factory defaults. Use the configuration wizard to enter new configuration settings.

How about just going to WCS and adding a new admin level user and then deleting the old?