If the connection still fails, you can try lowering the security requirements via Group Policy. Navigate to Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Security and set the "Security Layer" to RDP . 5. Alternative Connection Tools
Error code 0x904 typically appears when the Remote Desktop client or related components fail to install or update because of corrupted system files, conflicting software (antivirus/remote-access tools), missing Windows features, or problems with Windows Update / MS Installer. i remote desktop connection error code 0x904 install
The firewall on either the client or the remote server may be blocking the connection. Check Exceptions If the connection still fails, you can try
If you can access the host machine physically or via an alternative tool, resetting the certificate store often clears the error: conflicting software (antivirus/remote-access tools)
| Component | Role | Failure point with 0x904 | |-----------|------|---------------------------| | tscupgrd.exe | Upgrades RDP client version | Writing new mstscax.dll to System32 | | licmgr.exe | Manages RDP licenses | Creating MSLicensing registry hive | | RDPActiveX.msi | Installs RDP web control | Extracting to %ProgramFiles%\Remote Desktop | | dism.exe / cbs.dll | Servicing stack | Finalizing RDP feature installation (FOD) |
This article provides a "deep" analysis of the causes and a step-by-step resolution guide.