There are a few places where PW are stored. Since I'm not sure which one you are referring to, I will list them
1) For Windows Stored Application Passwords - Go To Your Control Panel, then Go into "Users". Choose a Username, then after you have selected a user, on the left side is a menu. Select "Manage My Network Passwords"
2) For Internet Explorer Passwords, Go to your Control Panel, then Select Internet Options. Then Select the Content Tab, then click on AutoComplete.
3) Or If it is a PW that is saved by a Cookie, delete your cookies. Go to your Control Panel, then Select Internet Options. General Tab, then click Delete Cookies.
Were one of those options what you needed?