Hi,
when prompted to log in, you should use the username and password of your account on the remote PC. No empty passwords are allowed. What is the format you are using to login? On Windows, the following are accepted:
1) User Principal Name: <username>@<domain>
2) Down-Level Logon Name: <domain>\<username>
3) Short format name, just ‘username’, domain is implicit.
See this article for more information about username formats: https://kb.nomachine.com/AR03S01118
You say that it doesn’t work. A quick way to chec is to open a CMD and type the command prompt ‘whoami’. It should return the username of your Windows account. Are you using that?