The "RPC Server is Unavailable" error in Windows is one of those cryptic messages that can disrupt workflows, especially when trying to access network resources, manage services, or connect to remote devices. Despite being a relatively common issue, detailed solutions are often buried in technical forums or Reddit threads. This guide will help you understand the causes and provide actionable fixes.
The error occurs when your computer cannot establish a connection with a remote system using the Remote Procedure Call (RPC) protocol. RPC is essential for communication between networked devices, as well as internal system processes.
Disabled RPC Services: Core Windows services like "Remote Procedure Call (RPC)" or "DCOM Server Process Launcher" might be disabled.
Firewall Blocking RPC Traffic: A misconfigured firewall can block RPC-related ports.
DNS Resolution Issues: Incorrect or outdated DNS settings can prevent proper communication between devices.
Corrupt or Missing Registry Keys: RPC relies on the Windows registry, and any corruption can cause errors.
Network Connectivity Problems: Issues with your network adapter or settings can disrupt RPC traffic.
1. Ensure RPC Services Are Running
Press Win + R and type services.msc, then press Enter.
Look for the following services:
Remote Procedure Call (RPC)
DCOM Server Process Launcher
RPC Endpoint Mapper
Ensure their Startup Type is set to Automatic:
Right-click on each service → Properties → Set Startup Type to Automatic → Click Start (if not running).
2. Check Your Firewall Settings
A misconfigured firewall may block essential RPC traffic. To fix this:
Press Win + S, type Windows Defender Firewall, and select it.
Click Allow an app or feature through Windows Defender Firewall.
Ensure that the following apps are allowed:
Remote Assistance
Remote Desktop
Add inbound rules for RPC ports (135 and dynamic ports):
Go to Advanced Settings → Inbound Rules → New Rule.
Select Port, enter 135, and allow the connection.
3. Verify Network Connectivity
Ensure that your network adapter and connection settings are properly configured:
Press Win + S, type Network Status, and select it.
Click Change adapter options.
Right-click your network adapter → Properties.
Ensure the following protocols are enabled:
Internet Protocol Version 4 (TCP/IPv4)
File and Printer Sharing for Microsoft Networks
Client for Microsoft Networks
Test your connection by pinging the target device:
Open Command Prompt and type:
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ping [TargetDeviceName or IP]
4. Check DNS Settings
RPC relies heavily on proper DNS resolution. To ensure it works:
Press Win + R, type ncpa.cpl, and hit Enter.
Right-click your network connection → Properties.
Select Internet Protocol Version 4 (TCP/IPv4) → Click Properties.
Ensure Obtain an IP address automatically and Obtain DNS server address automatically are selected. If using static settings, verify the DNS address is correct.
Flush and renew your DNS settings:
Open Command Prompt and run the following commands:
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ipconfig /flushdns
ipconfig /registerdns
5. Repair Corrupted Registry Keys
Warning: Modifying the registry can be risky. Proceed with caution and back up your registry first.
Press Win + R, type regedit, and hit Enter.
Navigate to:
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HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RpcSs
Verify that the Start key value is set to 2 (Automatic).
Repeat this for:
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HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RpcEptMapper
6. Reboot and Test
After applying the above fixes, reboot your system and test the functionality:
Try accessing a shared network folder.
Use a remote desktop connection.
Run a system management tool that previously triggered the error.
If the issue persists, consider these additional steps:
Run the System File Checker (SFC):
Open Command Prompt as an administrator and run:
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sfc /scannow
This will repair any corrupted system files.
Update or Reinstall Network Drivers:
Press Win + X → Device Manager.
Expand Network Adapters, right-click your adapter, and select Update Driver.
Reinstall Windows Components:
Open PowerShell as administrator and run:
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DISM /Online /Cleanup-Image /RestoreHealth
Regularly update your system to prevent registry corruption and ensure compatibility.
Use reliable DNS servers, such as Google Public DNS (8.8.8.8).
Regularly back up your Windows registry and important configurations.
The "RPC Server is Unavailable" error in Windows can disrupt workflows, but it’s usually caused by misconfigured services, network issues, or firewall settings. By following the steps in this guide, you can diagnose and resolve the problem effectively. If you encounter unique challenges or require additional assistance, forums like Reddit’s r/sysadmin or Microsoft’s community can be helpful resources.
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