Troubleshooting the “RPC Server Is Unavailable” Issue in Windows – 2025

Troubleshooting the “RPC Server Is Unavailable” Issue in Windows

The “RPC Server is Unavailable” error is one of the more frustrating problems Windows users may encounter, especially when trying to connect to networked devices, launch certain programs, or perform system-related tasks. RPC (Remote Procedure Call) is a vital communication protocol that allows different system processes to communicate across a network or within a computer.

When this service fails, users may receive the message:
“The RPC server is unavailable”
along with an error code such as 0x800706BA or 1722.

In this guide, we’ll explain what causes the RPC error and provide practical steps to fix it.

What Is RPC and Why Is It Important?

RPC stands for Remote Procedure Call. It is a protocol that enables one program to request a service from another program located either on the same machine or across a network. It plays a key role in Windows operations including:

• File and printer sharing

• Disk management

• Remote desktop and remote assistance

• Windows services and processes

If the RPC mechanism is interrupted, essential services and applications may stop working, resulting in this error message.

Common Causes of the RPC Server Unavailable Error

There are several reasons why this error can occur:

1. RPC Services Are Not Running

If the core RPC-related services are disabled or not running correctly, the system cannot establish connections.

2. Network Connectivity Issues

The RPC service relies on a stable network. If there are IP address conflicts, firewall restrictions, or DNS problems, the RPC call may fail.

3. Incorrect Registry Settings

Corrupt or misconfigured registry entries can block RPC communication.

4. Antivirus or Firewall Blocking RPC

Third-party firewalls or security software may prevent RPC ports (typically TCP port 135) from functioning.

Step-by-Step Solutions to Fix the RPC Error

Let’s go through the methods to identify and resolve the problem.

Step 1: Ensure RPC Services Are Running

You need to confirm that the correct services are active.

To check:

1. Press Windows + R, type services.msc, and press Enter.

2. In the Services window, locate and verify the following:

   • Remote Procedure Call (RPC) — Status should be Running and Startup type as Automatic.

   • DCOM Server Process Launcher — Also set to Running and Automatic.

   • RPC Endpoint Mapper — Ensure it is Running and Automatic.

If any of these are not running, right-click and choose Start, then set the Startup type to Automatic.

Step 2: Check Your Network Connection

RPC relies on a stable network connection.

Verify the following:

• You have an active network connection (wired or wireless).

• If connected to a domain or local network, try pinging the remote computer:

  css

  ping [computer-name]


• If ping fails, it might be a network or DNS issue.

Step 3: Allow RPC in Windows Firewall

The Windows Firewall may block RPC traffic. You need to enable the correct rule.

To enable firewall rules:

1. Open Control Panel > System and Security > Windows Defender Firewall.

2. Click Allow an app or feature through Windows Defender Firewall.

3. Make sure these services are checked:

   • Remote Assistance

   • Remote Desktop

   • RPC (TCP-In)

   • DCOM-In

If not listed, manually add inbound rules for TCP port 135 in the Advanced Settings of the firewall.

Step 4: Disable Third-Party Security Software Temporarily

Some antivirus software has aggressive network protection that blocks RPC services.

Try this:

• Temporarily disable your third-party firewall or antivirus.

• Retry the operation that was failing.

• If the RPC error goes away, consider adding an exception in your security software for RPC traffic.

Step 5: Verify IP and DNS Settings

Improper DNS resolution can prevent RPC from connecting to other machines.

Steps to reset and verify:

1. Open Command Prompt as administrator.

2. Run the following commands one by one:

   perl

   ipconfig /flushdns
ipconfig /wp-signup.phpdns
nbtstat -R
nbtstat -RR
netsh int ip reset
netsh winsock reset


3. Restart your computer.

Step 6: Check the Windows Registry (Advanced)

Warning: Editing the registry can cause serious issues. Proceed only if you’re comfortable.

To verify registry settings:

1. Press Windows + R, type regedit, and press Enter.

2. Navigate to:

   sql

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RpcSs


3. Check that the value Start is set to 2 (Automatic).

Also, inspect:

and ensure the Start value is 2.

If the values are incorrect, right-click and modify them to 2.

Always back up the registry before making changes.

Step 7: Use System File Checker and DISM

Corrupt system files might disrupt RPC communication.

Run these commands in Command Prompt (Admin):

Then, after completion:

These tools scan and repair damaged or missing system files.

Step 8: Reboot and Test

After applying the above fixes, restart your computer and test whether the RPC-related task or connection now works properly.

When to Consider a System Restore

If none of the above methods work and the problem started recently, use System Restore:

1. Open Start and search for Create a restore point.

2. Click System Restore, choose a restore point before the issue occurred.

3. Follow the prompts to roll back your system settings.

This may undo changes from software updates or registry edits that disrupted RPC.

Final Thoughts

The “RPC Server Is Unavailable” error can be frustrating, but it’s almost always solvable with a combination of service checks, network configuration, and firewall management. In many cases, simply ensuring that the RPC-related services are running and the network is stable can fix the problem.

If you’re still having trouble after trying everything, it may be worth checking for hardware-related network issues, corrupted Windows installations, or even consulting Microsoft Support for deeper diagnostics.