If the conflicting process is PID 4 (System), this typically indicates that Windows components like RRAS or ADFS are using the HTTP.sys driver. Resolve this by:
The error message blocks upgrades and installations of Veeam Backup & Replication (VBR). Starting with Veeam v13 , the software introduces a hardcoded architectural requirement for TCP Port 443 . It uses this port to handle its modernized REST API gateway, web user interface components, and identity management services.
If the server is a Hyper-V host running replication, the System process (PID 4) locks port 443. You can resolve this by reconfiguring Hyper-V to run over a custom port: Open the console. Right-click the host server and select Hyper-V Settings . Navigate to Replication Configuration .
The following applications and Windows components frequently conflict with Veeam on port 443:
If you need a quick fix to get Veeam running right away, you can forcefully terminate the occupying process.
netstat -noa | sls 443
Required Port 443 For Veeam Backup Replication Is Occupied By Another Application Link Jun 2026
If the conflicting process is PID 4 (System), this typically indicates that Windows components like RRAS or ADFS are using the HTTP.sys driver. Resolve this by:
The error message blocks upgrades and installations of Veeam Backup & Replication (VBR). Starting with Veeam v13 , the software introduces a hardcoded architectural requirement for TCP Port 443 . It uses this port to handle its modernized REST API gateway, web user interface components, and identity management services. If the conflicting process is PID 4 (System),
If the server is a Hyper-V host running replication, the System process (PID 4) locks port 443. You can resolve this by reconfiguring Hyper-V to run over a custom port: Open the console. Right-click the host server and select Hyper-V Settings . Navigate to Replication Configuration . It uses this port to handle its modernized
The following applications and Windows components frequently conflict with Veeam on port 443: Right-click the host server and select Hyper-V Settings
If you need a quick fix to get Veeam running right away, you can forcefully terminate the occupying process.
netstat -noa | sls 443
