If you are using Remote Desktop you should be aware that you can save your credentials to be able to connect without entering user name and password each time. But for some reason sometimes it does not work.
You try to connect with you saved credentials and a logon screen pops up with the message at the bottom that "The logon attempt failed". (screenshot)
This is because you entered wrong credentials first time and they were saved, so you need to delete your credentials, enter them again and choose to remember them.
However I was not able to do that, as many times as I tried to delete my credentials and then enter correct ones and save them, when reloging I always got "The logon attempt failed".
So I had to use hostname instead of IP address, when connecting, to be able to save my correct credentials and then successfully relogon without having to enter my password.
You might want to try this if above information does not solve your problem: