How to Fix RPC Server is Unavailable Error on Windows

July 2, 2026 By Nancy William No Comments 7 minutes

Constantly seeing the “RPC server is unavailable error” on Windows? This guide, updated June 2026, will help fix the issue.   

The RPC server is unavailable Windows error is one of the most frustrating issues you can encounter. It appears in everything from network scans, domain logins, certificate enrollments, and backups.

It can prevent you from connecting to remote computers, from accessing files, or even logging into your system.

This guide helps remove all the technical jargon, giving you quick and practical fixes to solve it.

What is RPC? What Causes the Error to Appear?

RPC, short for Remote Procedure Call, is a built-in Windows mechanism that allows different processes and computers to communicate with each other.

Think of it in this way: you ask to access a file on another computer or perform a task; RPC handles the request and connects you to the right service.

How A Standard RPC Connection Works

Let’s explain it in these words:

• Your computer (the client) dials a “receptionist” or “service” on TCP port 135 of the target machine.
• The service (Endpoint Mapper) listens to your request and assigns a temporary “office” (a dynamic port).
• You’re redirected to that new port to actually do your work.

The RPC error appears when this communication chain breaks at any point.

But what causes it? 

• The RPC service has stopped or is disabled. 
• A firewall is blocking TCP port 135 or the dynamic RPC ports (1024-65535 on older systems, 49152-65535 on Windows 8/Server 2012 and newer). 
• There are DNS or name resolution issues. 
• The target computer is offline or unreachable. 
• Network settings are misconfigured.

Run a Quick Diagnostic Checklist Before Fixing RPC Server Error

You shouldn’t be guessing what the issue is and where it lies. For that, here’s a checklist to narrow down the problem:

• Ping the target computer by IP address: if it doesn’t respond, then you have a network connectivity issue.
• Ping the target computer by name, for instance, ping SERVER01. If this fails but the IP ping works, you have a DNS problem.
• Check that the target computer is turned on; it might sound obvious, but it is usually where the issue lies. 
• Verify the RPC service is running on the target machine. To do that, open services.msc and look for “Remote Procedure Call (RPC)”; it should show “Running”.

How to Fix RPC Server is Unavailable Error (5 Fixes from Simple to Advanced)

Let’s get started:

Fix 1: Verify and Restart Core RPC Services

This is one of the most effective fixes on the list, especially if the services have stopped or been disabled. Here’s what to do:

On the PC displaying the error:

• Press “Win + R,” type services.msc, and press “Enter.”
• Locate these three essential services and ensure each is set to “Automatic” and “Running”:

Here’s what the service names are and their required status: 

• If any of these services are stopped, right-click it and select “Start.”
• Also, if the startup type is “Disabled,” change it to “Automatic.”
• Now you can restart your PC and the changes will automatically be applied. 

TIP – The RPC Locator is often not needed for client operations and can be left disabled.

Fix 2: Check the Windows Firewall Rules (Port 135 Block)

The Windows Firewall frequently blocks the RPC traffic and is a primary suspect for this error. There are two methods that you can use for it: 

Method A: Create an Exception for Remote Administration

• Open “Control Panel” > “System and Security” > “Windows Defender Firewall.”
• Click “Allow an app or feature through Windows Defender Firewall.”
• Scroll down and check the boxes for “Remote Assistance” and “Remote Desktop” for both “Private” and “Public” networks.

Method B: Check for Explicit Port Blocks

• Open “Windows Defender Firewall” with “Advanced Security.”
• Click “Inbound Rules” and look for any rules that might be blocking TCP port 135.
• If you find one, right-click on it and select “Disable.” This is temporary or testing.

NOTE – If you’re using a third-party firewall, ensure you consult its documentation first. This is to make sure RPC traffic on TCP port 135 is allowed.

Fix 3: Enable “File and Printer Sharing for Microsoft Networks”

This network component is essential for RPC communication, particularly for administrative tasks. Here’s what to do to fix RPC server is unavailable:

• Open “Control Panel” > “Network and Sharing Center” > “Change adapter settings.”
• Right-click your active network adapter, which is your Wi-Fi or Ethernet, and select “Properties.”
• Ensure “File and Printer Sharing” for Microsoft Networks is checked. If it’s missing, click “Install” > “Service” > “File and Printer Sharing for Microsoft Networks” > “OK.”
• Click “OK” to save.

Fix 4: Clean Up DNS and Network Settings

Next on how to fix RPC server is unavailable is via cleaning up DNS and network settings. This is commonly caused by broken DNS resolution. Here’s what to do: 

1. Open “Command Prompt” as “Administrator.”
2. Run these commands one by one to reset your network stack :
3. text

ipconfig /flushdns

ipconfig /registerdns

1. netsh winsock reset
2. Now, restart your computer.

Fix 5: The Advanced Troubleshooting Toolkit

Last on the list on how to fix RPC server is unavailable error is via the advanced troubleshooting Toolkit. This fix is if the simpler ones haven’t worked. These tools will help you pinpoint the exact issue. Here’s how to get started: 

Tool 1: PortQry

Microsoft’s PortQry is the go-to tool for RPC diagnostics . From a command prompt on the client, run:

text

Portqry.exe -n <ServerIP> -e 135

Replace <ServerIP> with the target computer’s IP. Analyze the output :

• If it shows LISTENING, port 135 is open.
• Look for a line like UUID: d95afe70-a6d5-4259-822e-2c84da1ddb0d … [49664]– this is the dynamic port EPM assigned.
• If this fails, you have a firewall or network issue.

Tool 2: Check Group Policy Restrictions

In some cases, Group Policy can block RPC access. Run the following in an elevated command prompt to generate a policy report:

text

gpresult /h appliedgpo.html

Open the generated .html file and look under “Policies” > “Windows Settings” > “Security Settings” > “Local Policies” > “User Rights Assignment for”:

• Access this computer from the network; however, ensure the user/computer account is listed.
• Deny access to this computer from the network. Ensure that the user/computer account is not listed. 

Tool 3: Registry Check for DCOM

DCOM must be enabled for RPC to function. To do that: 

• Open Regedit and navigate to HKEY_LOCAL_MACHINE\Software\Microsoft\OLE.
• Find the EnableDCOM value. It should be Y, but if it’s N, change it to Y and restart.

Cannot Fix RPC Server is Unavailable Error – System Restore

If you happened to try all the fixes on the list, everything has failed, and the error still persists, a System Restore is required. It can help revert your system to a state before the issue begins. Here’s what to do:

• Open “Control Panel” > “Recovery” > “Open System Restore.” 
• Select a restore point dated before you started experiencing the error.
• Follow the prompts to restore your system.

To Conclude

You now know how to fix RPC server is unavailable error. However, to ensure that this error doesn’t occur again, here’s what you need to do: 

• Don’t disable core RPC services because they are critical for Windows operation.
• Keep your firewall configured correctly to ensure TCP 135 and dynamic RPC ports are allowed.
• Maintain proper DNS records by regularly checking that computer names resolve correctly.
• Keep your system updated always to ensure patches often fix underlying RPC issues.