For quite some time I'd struggled with the occasional problem of cached passwords in Windows. You've probably had this happen before. You have some network resource such as a file server share that you need to access. When accessing it you are prompted for Windows credentials. So you put in a username and password, and because you don't want to go through that process every time, you select "Remember my password".
But then one day something doesn't work or you simply want to change how you are connecting to that resource.
I originally thought it might have something to do with the cached network connection itself. Going into a command prompt and typing "net use" will show you all the network resource connections you've made since the last login/boot. You can also use "net use" to disconnect them. However, if you've saved a password for the resource you still won't be prompted for one even on a new connection.
The question remains: Where exactly do those passwords go??
Go to Start -> Control Panel -> User Accounts
Select the "Manage Passwords" button. You'll get the "Stored User Names and Passwords" dialog:
This contains Microsoft Passport/Windows Live logins that are associated with the current logged in user profile as well as the saved passwords for network connections. You can add, remove or change as you like.