How to Remove Stored username and Passwords !

To remove the Stored User Names and Passwords from your system, try this:
Click Start, Run and type Control keymgr.dll
Remove the entries from the list.

The other ways to access this dialog are:
Type Control Userpasswords2 in RUN box, click Advanced, Manage Passwords
-or-
From Control Panel, select your User Account, click Manage your network passwords

It Works