If you use a Microsoft Account to log into a Win10 or 11 machine (which is the default at this point in time, you have to try hard to use a Local Account), you may be unable to RDP/MSTSC to the machine with that account. Here’s how to fix it.

On the PC hosting the remote desktop session (running Pro or Enterprise, Home does not support RDP), run the following command (I found I needed to open a CMD window first, sometimes using the Run UI works), replacing the example email address with your Microsoft Account email address that you use to login to the computer.

runas /u:MicrosoftAccount\user@domain.com winver

This command runs the “winver” program under the credentials of the user account specified. It sounds (and is) pretty simple, but what it does in the background is caches your Microsoft Account credentials. Since your local user account had no password, it wasn’t eligible for RDP use even if it has appropriate permissions otherwise. After supplying the password and pressing Enter, you’ll know it worked if you see the About Windows dialog box open. Go ahead and close it and the terminal window — you’re all done.

At this point, you should be able to connect to the remote computer using the same account & password you just used to run the above command.