IT Error Decoder
Windows Admin

How to Fix The RPC server is unavailable

Error message

The RPC server is unavailable. (0x800706BA)

If you're seeing "The RPC server is unavailable", you're not alone. Here's what it means, why it happens, and the steps to resolve it.

What this error means

Your computer tried to talk to a remote service over RPC and either couldn't reach it, couldn't authenticate, or the service wasn't listening.

Why this happens

Firewall blocking RPC/Endpoint Mapper (TCP 135) or the dynamic RPC port range, the remote service stopped, name resolution failure, or wrong credentials.

Step-by-step fix

  1. Confirm name resolution and basic reachability.

    command
    ping <remote>
Resolve-DnsName <remote>

  2. Test the RPC endpoint mapper port.

    command
    Test-NetConnection -ComputerName <remote> -Port 135

  3. On the target, confirm the relevant service is running (e.g., `Server`, `Remote Registry`, `WMI`).

    command
    Get-Service -ComputerName <remote> -Name <name>

  4. Allow RPC and the dynamic port range through firewalls between source and destination.

Affected products

Windows Admin

Still broken? Try these

  • Capture a Wireshark trace on TCP 135 to see whether SYNs are answered.
  • If across domains, check the trust relationship and DNS forwarders.
  • Reset Windows Firewall to defaults and retest.

Related errors

Frequently asked questions

What does "The RPC server is unavailable" mean?

Your computer tried to talk to a remote service over RPC and either couldn't reach it, couldn't authenticate, or the service wasn't listening.

What causes "The RPC server is unavailable"?

Firewall blocking RPC/Endpoint Mapper (TCP 135) or the dynamic RPC port range, the remote service stopped, name resolution failure, or wrong credentials.

How do I fix "The RPC server is unavailable"?

1. Confirm name resolution and basic reachability. 2. Test the RPC endpoint mapper port. 3. On the target, confirm the relevant service is running (e.g., `Server`, `Remote Registry`, `WMI`). 4. Allow RPC and the dynamic port range through firewalls between source and destination. Always test changes in a non-production environment first.

Browse more errors in Windows Admin: Fix Windows administration errors. Access denied, RPC server unavailable, trust relationship failures, Group Policy errors, and network path issues. Or paste your own error into the error decoder tool to find a match. You can also go back to the homepage to browse common errors by topic.