Open Control Panel
User Accounts
Move to Credential Manager
Manage Windows Credentials
Click one of the entries in the list and expand it, you can then click the Remove option to clear it.
===============================
Press Win+R keys
In the Run menu type:
rundll32.exe keymgr.dll, KRShowKeyMgr and hit the Enter key
You’ll see the Stored Usernames and Passwords window. To remove a saved network credential you can select one of the entries and click Remove.