Open Network Folders With Different Username / Password Without Deleting Saved One

Sometimes I need to login to server shared folder with different username and password than saved one in "manage network password" or "windows credentials" (windows 7). At that time, I have to delete the previous one in "managed network password", then open the shared folder with new username, again save the old once once it is done.Is there anyway I can just open with different usernames without deleting the saved one? Different users have different privileges in server. Similarly, how to delete temporarily network cached passwords without restarting? I tried net user * /delete but it doesn't work?