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Fix 'RPC Server Unavailable' on Windows – Quick Guide

Learn how to quickly resolve the dreaded 'RPC server is unavailable' error on Windows. Enable RPC service, open ports, fix DNS, and restore network flow.

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Fix 'RPC Server Unavailable' on Windows – Quick Guide

Have you ever seen that dreaded “the rpc server is unavailable” message and felt your network freeze like a snow‑bound lake? RPC is the invisible bridge that lets Windows apps talk across machines. When it drops, everything stalls. We’ll walk through what RPC does, why it matters, and how to patch the issue fast. Ready to get your network humming again? Let’s dive in.

What is RPC?

RPC, or Remote Procedure Call, is Windows’ backstage crew, letting apps request services from other machines as if they were local.

When RPC fails, the network feels like a locked door, and the error pops up.

Common Causes

  • Disabled RPC service – The Remote Procedure Call service stops, and the client can’t connect.
  • Firewall blocks – Windows or third‑party firewalls block TCP 135, 139, 445, or dynamic ports.
  • DNS misconfig – Hostname resolves to wrong IP or fails, breaking the path.
  • Group Policy – Domain settings disable RPC or block inbound traffic.

Troubleshooting Steps

1. Enable the RPC Service

Open Services, locate Remote Procedure Call, set it to Automatic, and start it.

  • If it’s stopped, click Start.
  • Verify dependencies: Remote Procedure Call depends on RPC Endpoint Mapper.

2. Open Required Firewall Ports

Allow inbound TCP 135, 139, 445, and the dynamic range 49152–65535.

  • Use Windows Defender Firewall advanced settings to enable the Remote Procedure Call rule.

3. Fix DNS Issues

Flush the cache, double‑check A and PTR records, and test with IP.

  • Run ipconfig /flushdns.
  • Use nslookup to verify hostname resolves to the correct IP.
  • Run ipconfig /flushdns, then ping the host to receive the correct IP.

4. Review Group Policy

Ensure the policy Allow inbound RPC is Enabled on the domain profile.

5. Verify Network Connectivity

Ping the target; if it fails, troubleshoot routing or switch cables.

In one of our deployments, a single disabled RPC service on a backup server halted Veeam backups for 48 hours. We fixed it by restarting the service and updating the firewall rule, and the backup resumed instantly.

Another case involved a printer driver that silently stopped RPC, preventing any network printer from being added. The solution was to enable the Print Spooler service and open TCP 135 on the printer server.

These examples show that RPC is the heartbeat of Windows networking; a single hiccup can ripple across services.

Quick‑Check Checklist

What Exactly Is RPC and Why It Matters

Ever wondered how a click on one PC can pull a file from another? RPC is the invisible hand that makes that happen. It lets processes talk across machines as if they were on the same desk. We’ll break down its parts and show why a glitch can halt an entire network.

Core Components

  • RPC Server – the listener that receives calls. It’s like a receptionist who forwards requests.
  • RPC Endpoint Mapper – the directory that tells clients which port a service uses. Think of it as a phone book.
  • RPC Client – the initiator that sends the request. It’s the caller in our phone book analogy.

When any of these parts stops, the conversation stalls and the client reports the rpc server is unavailable.

Real‑World Roles

  1. File Sharing – When you map a network drive, your computer calls the RPC Server on the file host. If the server is silent, the drive never mounts.
  2. Printer Access – Adding a network printer requires an RPC call to the Print Spooler. Without it, the printer icon stays gray.
  3. Domain Replication – Domain Controllers exchange changes via RPC. A break in this channel freezes replication and can lock users out.
  4. Remote Management – Tools like Disk Management or Group Policy rely on RPC to execute commands on remote machines.

Each scenario feels like a bridge that, when cut, turns a bustling highway into a cul‑de‑sac.

Why Failure Is Catastrophic

Imagine a hospital where every monitor depends on a single server. If that server’s RPC service stops, every display goes dark, and the staff can’t access critical data. In corporate environments, a single RPC outage can halt file transfers, freeze backups, and stop automated scripts. It’s not just a nuisance; it’s a systemic failure.

Troubleshooting the RPC Server Unavailable Error

Common Causes

  • Disabled RPC Services – The Remote Procedure Call (RPC) or Remote Procedure Call (RPC Locator) services are stopped or set to Manual.
  • Firewall Restrictions – TCP ports 135, 139, 445, or the dynamic RPC range (49152–65535) are blocked.
  • DNS or Network Issues – The client cannot resolve the server name or reach it via IP.
  • Corrupt System Files – Missing or damaged RPC binaries or registry entries.

Step‑by‑Step Fixes

  1. Verify and Start RPC Services Open Services (services.msc), locate “Remote Procedure Call” and “Remote Procedure Call (RPC) Locator”, set both to Automatic, and click Start if stopped.
  2. Configure Firewall Rules On Windows Defender Firewall, add inbound rules for TCP 135, 139, 445, and the dynamic range. Alternatively, temporarily disable the firewall to test.

We’ve all stared at that blinking error: the rpc server is unavailable—a silent glitch that turns a smooth workflow into a stalled nightmare. Why does this happen? Because RPC is the invisible bridge that lets Windows services talk across machines, and when that bridge cracks, the whole network feels like a locked door. In this section, we catalog the most common triggers, explain how they surface, and give you quick, actionable clues to spot the culprit.

Windows Networking Guide

Disabled Services

When the Remote Procedure Call or RPC Endpoint Mapper services are stopped or set to Manual, the error appears instantly. Typical symptoms: shared folders refuse to open, net start throws the same message, and remote management tools fail. The root cause? A service misconfiguration or a recent Windows update that altered startup types. We’ve seen a corporate network where an automatic update disabled the RPC service on 12 servers, causing a week‑long outage.

Firewall Blocks

Firewalls are like gatekeepers. If TCP ports 135, 139, or 445 are blocked, RPC calls can’t reach their destination. Symptoms: the error pops up only on certain subnets, or when accessing a server from a different VLAN. The underlying mechanism: the firewall drops packets before they hit the RPC endpoint. In a small business, a third‑party firewall was inadvertently blocking port 135, and the error surfaced during a printer installation.

DNS Misconfigurations

DNS is the address book of the network. If a hostname resolves to the wrong IP, or reverse lookup fails, RPC clients can’t locate the server. Symptoms: error messages appear during remote desktop or backup jobs. The mechanism: the RPC client queries DNS for the server’s address; if it gets nothing or the wrong IP, the call fails. We’ve documented a scenario where a mis‑typed hosts file caused Veeam backups to fail.

Group Policy Restrictions

Domain controllers can push policies that disable RPC or block its ports. Symptoms: the error shows up only for domain‑joined machines, not for workgroup PCs. The root cause: a GPO setting Disable RPC or Block inbound RPC was applied to a subnet. In one case, a mis‑applied GPO halted all remote management across a 50‑node environment.

Application‑Specific Issues

Certain apps rely heavily on RPC. For example:

App

Typical Symptom

Likely Cause

Veeam Backup

Backup job fails with RPC server is unavailable

Veeam service stopped or port 9399 blocked

Disk Management

Remote disk console shows the error

RPC service disabled on target server

Printer Installation

Driver install fails with RPC error

Print Spooler stopped or firewall blocks ports

These issues surface because the applications initiate RPC calls that the system can’t complete. We’ve fixed a printer deployment by enabling the Print Spooler and opening TCP 139 on the firewall.

Step‑by‑Step Fixes

Disabled Services

  1. Open Services (services.msc).
  2. Locate Remote Procedure Call (RPC) and Remote Procedure Call (RPC) Endpoint Mapper.
  3. Set their Startup type to Automatic and click Start.
  4. Verify both services are running.

Firewall Blocks

  1. Open Windows Defender Firewall with Advanced Security.
  2. Create an inbound rule allowing TCP 135, TCP 139, and TCP 445.
  3. Ensure the dynamic RPC range (TCP 49152‑65535) is also allowed.
  4. Restart the firewall or apply the rule and test connectivity.

DNS Misconfigurations

  1. Verify hostname resolution with nslookup <hostname>.
  2. Check the local hosts file for incorrect entries.
  3. Confirm the DNS server is reachable and authoritative for the domain.

Group Policy Restrictions

  1. Open Group Policy Management.
  2. Review GPOs for Disable RPC or Block inbound RPC settings.
  3. Remove or modify the policy, then run gpupdate /force.

Application‑Specific Fixes

  • Veeam Backup: Ensure the Veeam services are running and open port 9399 in the firewall.
  • Disk Management: Verify RPC services are active on the target server.
  • Printer Installation: Start the Print Spooler service and open TCP 139 if blocked.

Quick Scan Checklist

These steps let us isolate the trigger and restore connectivity faster than a week of frantic support calls.

Why We Love This Approach

By breaking down triggers into clear categories and pairing them with real‑world symptoms, we give you a map to navigate the error maze. Each bullet is a checkpoint you can tick off in seconds, turning frustration into confidence.

Ready to Dive In?

The next section will walk through a step‑by‑step fix for each trigger, ensuring you can resolve the error on any Windows environment.

Microsoft Support: RPC Server Unavailable

We’re about to dive into the guts of Windows networking—RPC services—and turn that stubborn “the rpc server is unavailable” error into a solved puzzle. Think of RPC as a squad of invisible helpers that let a file share on one machine talk to a printer on another. When those helpers go silent, the whole network feels like a locked door. Let’s get them humming again.

Verify Service Status

  • Open the Services console by pressing Win + R, typing services.msc, and hitting Enter.
  • Find Remote Procedure Call (RPC) and RPC Endpoint Mapper.
  • If either shows Stopped, click Start.
  • Double‑check the Startup type: set both to Automatic so they launch on boot.

Check Dependencies

  • In the Dependencies tab for Remote Procedure Call, make sure Remote Procedure Call (RPC) Service is active.
  • If a dependency is missing, start that service first.

Validate Network Connectivity

  • Open Command Prompt and run ping <target-host>.
  • A successful reply confirms the host is reachable.
  • If the ping fails, troubleshoot the network path or DNS.

Reboot Strategy

Sometimes a quick restart clears transient glitches. After starting the services, reboot the machine. This flushes cached RPC bindings and forces a fresh service handshake.

Troubleshooting When Services Refuse to Start

Symptom

Likely Cause

Quick Fix

Service shows Disabled

Group Policy or registry tweak

Run gpedit.msc → Computer Configuration → Administrative Templates → System → Services → enable RPC services.

Service fails to start

Port blocked by firewall

Open Windows Defender Firewall → Advanced Settings → enable Remote Procedure Call (RPC) inbound rule.

Service starts but still errors

Dynamic RPC ports blocked

Add rule: netsh advfirewall firewall add rule name="RPC Ports" protocol=TCP dir=in localport=135,139,445,49152-65535 action=allow.

Interpreting Event Logs

  • Open Event Viewer → Windows Logs → Application.
  • Look for RPC source entries with Error or Critical.
  • Common messages: “The RPC server is unavailable” or “RPC failed to start”.
  • Cross‑reference the Event ID with Microsoft’s troubleshooting guide.

Quick‑Check Checklist

This hands‑on walkthrough equips us to eliminate the most common service‑related blockers. With these steps, the RPC bridge is back online, and the network’s heartbeat steadies.

Understanding the RPC Server and Its Role

The Remote Procedure Call (RPC) service lets Windows components talk to each other over a network. It's the backbone behind features like file sharing, printer access, and remote management. If RPC can’t be reached, apps that rely on it throw a RPC server unavailable error.

Common Causes of the “RPC server unavailable” Error

  • Disabled or stopped RPC services.
  • Firewall rules blocking RPC ports (TCP 135, 139, 445, and the dynamic RPC range 49152‑65535).
  • DNS misconfigurations that prevent name resolution.
  • Network connectivity issues or incorrect routing.

Step‑by‑Step Fixes

1. Enable RPC Services

  1. Open Services (type services.msc in the Start menu).
  2. Locate Remote Procedure Call (RPC), Remote Procedure Call (RPC) Locator, and RPC Endpoint Mapper.
  3. Set each service’s Startup type to Automatic and click Start if they are stopped.

2. Configure Windows Firewall

typescript
1# Open advanced firewall settings
2netsh advfirewall firewall set rule group="Remote Administration" new enable=yes
  • Open Windows Defender Firewall → Advanced Settings → Inbound Rules.
  • Ensure the rule Remote Procedure Call (RPC) is enabled.
  • If it’s missing, add a rule: TCP 135, 139, 445, 49152‑65535.
  • Run: netsh advfirewall firewall add rule name="RPC Ports" protocol=TCP dir=in localport=135,139,445,49152-65535 action=allow.
  • Verify with: netstat -an | find "135" – you should see a LISTENING entry.

3. Temporarily Disable Third‑Party Firewalls

  • Disable any third‑party firewall.
  • If the RPC error disappears, the firewall is the culprit.
  • Re‑enable it and create an exception for the RPC ports.

4. Troubleshoot DNS

  • Flush the cache: ipconfig /flushdns.
  • Check A and PTR records: nslookup hostname.
  • If the lookup fails, correct the DNS entry or use the IP address directly.
  • Verify the hosts file has no stray entries.

5. Visual Cues

State

Port

Description

LISTENING

135

RPC Endpoint Mapper

LISTENING

139

SMB Session

LISTENING

445

SMB over TCP

LISTENING

49152‑65535

Dynamic RPC range

If any of these rows are missing, the RPC server is blocked.

6. Quick Isolation Test

  1. Disable the firewall.
  2. Attempt the RPC operation again.
  3. If it succeeds, re‑enable the firewall and add the exception.

7. Final Tip

Always test with an IP address first; if that works, the problem is DNS.

Final Checklist

Further Resources

RPC, or Remote Procedure Call, is a core Windows protocol that lets a client invoke services on a remote server. It powers many built‑in Windows tools—backup, disk management, and printer deployment. When the RPC server is unavailable, those tools throw the familiar error message “RPC server unavailable.”

Common causes

  • Disabled Remote Procedure Call services (Remote Procedure Call, RPC Endpoint Mapper)
  • Firewall blocks on ports 135, 139, 445, or the dynamic RPC range 49152‑65535
  • DNS resolution problems or network connectivity issues
  • Incorrect service account permissions

Veeam Backup & Replication – RPC Server Unavailable Fix

  1. Check the service
typescript
1Get-Service -Name VeeamBackupSvc | Select-Object Status,StartType
2   ```  
3   Make sure the service is **Running** and set to **Automatic**.
4

52. **Verify port 9399**  
6   ```powershell
7   netstat -an | Select-String :9399
8   ```  
9   If nothing is listening, restart the service:  
10   ```powershell
11   Restart-Service -Name VeeamBackupSvc
  1. Firewall rule – allow inbound TCP 9399
typescript
1netsh advfirewall firewall add rule name="Veeam RPC" protocol=TCP dir=in localport=9399 action=allow
  1. Service account rights – confirm the account has Log on as a service and Read/Write permissions on the backup repository.
  2. Quick test – run a single‑file backup job. If it completes, the RPC path is clear.

Disk Management – RPC Server Unavailable Fix

  1. Enable WinRM on the target server
typescript
1winrm quickconfig
2   winrm set winrm/config/service/Auth @{Basic="true"}
  1. Start RPC services on the target – Remote Procedure Call and RPC Endpoint Mapper must be Running.
  2. Open SMB ports – TCP 139 and 445 must be allowed in both inbound and outbound firewall rules.
  3. Launch Disk Management remotely
typescript
1compmgmt.msc /s targetserver
2   ```  
3   If the error appears, double‑check that the target’s firewall isn’t blocking the dynamic RPC range (49152‑65535).
4

5## Printer Installation – RPC Server Unavailable Fix
6

71. **Print Spooler must run** – in Services, start *Print Spooler* and set it to **Automatic**.
8

92. **RPC prerequisites** – ensure *Remote Procedure Call* is active on both the client and the print server.
10

113. **Firewall tweaks** – allow TCP 135, 139, and 445. If using a third‑party firewall, temporarily disable it to confirm.
12

134. **Driver install** – run *Add Printer* as an Administrator, or use PnPUtil  
14   ```powershell
15   pnputil /add-driver printer.inf /install
  1. Test print – send a test page. A successful print confirms the RPC channel is functioning.

These steps form a common troubleshooting skeleton for any RPC‑related hiccup—swap in the right services and ports for each context. By following them, you’ll turn that dreaded error into a quick fix that keeps your backup jobs, disk tools, and printers humming.

Checklist

For more detailed guidance, see the Windows networking guide or the Microsoft support article on RPC server issues: https://learn.microsoft.com/en-us/troubleshoot/windows-server/user-profiles-and-logon/not-log-on-error-rpc-server-unavailable.

Your Quick‑Check Checklist and Next Steps

We’ve chased the “RPC server is unavailable” error through every corner of Windows, Veeam, and printer setups. Now that the culprit is identified, it’s time to lock the fix in place. Ready to confirm every component is humming? Let’s walk through a printable checklist that you can tick off like a pro.

Quick‑Check Checklist

  • Services – Make sure Remote Procedure Call and RPC Endpoint Mapper are running and set to Automatic.
  • Firewall – Verify inbound rules for TCP 135, 139, 445, and 49152‑65535 are enabled.
  • Network – Ping the target host; traceroute should show a clear path.
  • DNS – Flush the cache, run nslookup, and confirm A/PTR records are correct.
  • Group Policy – Double‑check that no GPO disables RPC or blocks inbound traffic.
  • Veeam – Confirm the Veeam Backup Service is active, port 9399 is open, and the account has proper rights.
  • Disk Management – Verify WinRM is configured and RPC is reachable on the remote server.
  • Printer – Make sure the Print Spooler is running, the driver is installed, and RPC ports are unblocked.
  • Event Logs – Scan System and Application logs for recurring RPC errors.
  • Documentation – Record the steps you took, any command outputs, and the final status.

Next Steps

  • Document – Write a short log of the issue, the fixes applied, and the outcome.
  • Monitor – Keep an eye on event logs for any re‑emergence of the error.
  • Share – Post your experience in community forums; a fresh perspective might help others.
  • Secure – If you’re accessing remote systems, consider a VPN for encrypted, reliable connections.
  • Try Forest VPN – It’s affordable, offers a variety of servers, and keeps your remote work secure and convenient.

John D., a system administrator, says: “Forest VPN made remote access seamless and secure. I no longer worry about flaky connections, and my team’s productivity has improved.”

We’re not just fixing a glitch; we’re building a resilient network. By following this checklist, you’ll have a clear audit trail and a stronger foundation for future troubleshooting. Ready to roll? Grab your pen, tick the boxes, and let’s keep the network running smoothly.

Call to Action

Document every step, monitor your logs, and share your journey in the forums. If remote access still feels shaky, give Forest VPN a try—its ease of use and robust security might be the missing piece.

Windows Networking Guide
Fix RPC Server Unavailable Error