Security hardening or system modifications can block the NETWORK SERVICE account from reading the RDP certificate's private key.
A second, though less common, trigger for 0x904 post-installation involves the service. On Windows Server editions (2016, 2019, 2022), if you install the RDS role but fail to properly configure a licensing server, the system enters an initial grace period (120 days). However, certain cumulative updates can prematurely enforce license validation. If the licensing service is stopped or misconfigured, the RDP stack rejects incoming connections with a non-specific error—often 0x904—before the login prompt fully renders.
Ensure Windows Firewall allows mstsc.exe and that third-party antivirus software is not blocking the connection. i remote desktop connection error code 0x904 install
Locate the certificate issued to the computer's name and look at the .
The error often appears because the HKEY_CLASSES_ROOT\RDP keys are missing. This is common after using registry cleaners like CCleaner. Security hardening or system modifications can block the
Check the Microsoft Q&A forum for 0x904 or use the Get-WindowsErrorReporting PowerShell cmdlet to generate a detailed crash log.
: Rename-Item -path "C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys" -NewName "MachineKeys_old" Locate the certificate issued to the computer's name
Windows Defender Firewall often blocks incoming remote connections by default.