How to Resolve RPC Server is Unavailable Error on Windows

Encountering the "RPC Server is Unavailable" error can be a major headache, as it blocks access to essential resources such as printers and shared files. This guide aims to shed light on the underlying causes and offers easy-to-follow steps to help you tackle this frustrating issue head-on.

What is RPC?

Remote Procedure Call (RPC) is a vital communication mechanism that enables programs on different computers within a network to interact seamlessly. It acts as a messenger system, facilitating data exchange and resource sharing between devices. When this communication pathway breaks down, the "RPC Server is Unavailable" error emerges.

Common Causes of the "RPC Server is Unavailable" Error

• Network Glitches:
  • Unstable internet connection (Wi-Fi or Ethernet).
  • Misconfigured network settings (IP address conflicts, incorrect subnet mask).
  • Router or modem malfunctions.
• Firewall Interference:
  • Windows Firewall or third-party firewalls blocking necessary RPC ports.
• Service Disruptions:
  • RPC service or related services (like DCOM) disabled or stopped.
• DNS Resolution Problems:
  • Incorrect DNS server settings hindering server location.
• Port Configuration Issues:
  • Blocked or misconfigured ports essential for RPC communication.
• Corrupted System Files:
  • System file corruption interfering with RPC service functionality.

Identifying the "RPC Server is Unavailable" Error

• Windows Error Messages: Explicit error messages stating "The RPC server is unavailable."
• Network Access Failures: Inability to access shared folders, printers, and other network resources.
• Administrative Tool Issues: Difficulty accessing administrative tools like Active Directory Users and Computers.
• Event Viewer Logs: Error logs related to RPC communication (Event ID 1722) in the Event Viewer.

How to Fix the "RPC Server is Unavailable" Error

1. Verify RPC Services are Running:
   • Start by opening Services (just type services.msc in the Run dialog) and make sure these services are set to "Automatic" and currently running:
     
     • Remote Procedure Call (RPC)
     • DCOM Server Process Launcher
     • RPC Endpoint Mapper
2. Check Network Connectivity:
   • Use the ping command in Command Prompt to see if you can reach the target server.
   • Troubleshoot any network issues you might encounter, like a weak Wi-Fi signal, cable problems, or even restarting your router or modem.
   • Also, keep an eye out for any IP address conflicts.
3. Allow RPC Traffic Through the Firewall:
   • Configure Windows Firewall or your third-party firewall to allow File and Printer Sharing, Remote Administration, and the necessary RPC ports (135, 445, and dynamic RPC port range).
4. Verify DNS Configuration:
   • Run the nslookup command to check if your DNS server is resolving correctly.
   • Make sure your DNS server settings are correct in your network adapter properties.
5. Check Port Configuration Issues:
   • Use the netstat command to see if port 135 is listening.
   • Verify the dynamic port range by running netsh int ipv4 show dynamicport tcp.
   • Adjust your firewall rules if needed.
6. Repair or Restore Corrupted System Files:
   • Run the System File Checker (sfc /scannow) and DISM (dism /online /cleanup-image /restorehealth) to fix any corrupted system files.
7. Check Active Directory Configuration (for Domain Environments):
   • Test your domain controller connectivity with dcdiag /test:connectivity.
   • Look for any Active Directory replication issues using repadmin /replsummary.

The "RPC Server is Unavailable" error can arise from a variety of issues, such as network troubles, service misconfigurations, or firewall restrictions. By carefully following these troubleshooting steps, you can effectively identify and resolve the problem, ensuring smooth network communication and access to shared resources.

Relevant Articles

• Troubleshooting Remote Procedure Call (RPC) problems in Windows: This article provides general guidance on troubleshooting RPC issues, including common causes and resolution steps.

  • URL: https://learn.microsoft.com/en-us/troubleshoot/windows-client/networking/rpc-errors-troubleshooting

• Remote Procedure Call (RPC) overview: This article provides a general overview of RPC and its role in Windows. It may help you understand the underlying technology and identify potential issues.

  • URL: https://learn.microsoft.com/en-us/windows/win32/rpc/rpc-start-page

• Services (services.msc): This article describes the Services console, where you can manage and troubleshoot various Windows services, including those related to RPC.

  • URL: https://answers.microsoft.com/en-us/windows/forum/all/what-services-in-servicesmsc-do-i-need-to-enable/2e444a68-4fc4-427b-be08-221f0b57865d