AO3 and Stoic Joker, No offense, but your suggestions are incorrect since Microsoft Passport is not tied to IE, therefore clearing out saved usernames/passwords from IE will not clear out those from Microsoft Passport.  cyberguest, I strongly advise you to follow my method as this is the only correct way to do this. Method #1: You will need to modify/create a key within the system. Open the Registry Editor, and navigate to the key: HKEY_LOCAL_MACHINE\ SYSTEM\ CurrentControlSet\ Control\ Lsa  Create a Value called "disabledomaincreds" and set it to "1". Reboot will finalise the process.  Note: This is generally only useful if you are setting up a system to be used by many users.  Key Details:  Machine Key: [HKEY_LOCAL_MACHINE\ SYSTEM\ CurrentControlSet\ Control\ Lsa]  Value Name: disabledomaincreds  Data Type: REG_DWORD (DWORD Value)  Data Value: "1" = disable : "0" = enable  Method #2 Here's a faster, safe, alternate way: must be logged in as ADMIN  Go to Start + Control Panel + User Accounts + Choose your account + "Manage my network passwords" at the top left + Then delete whichever MSN accounts you don't need.