Understanding the RPC Server Error

The Remote Procedure Call (RPC) protocol is a critical behind-the-scenes technology that allows different processes on your computer or across a network to communicate with each other. Think of it as a standardized language and delivery system that software components use to request services from one another. For example, when you try to open a file from a network drive, your computer uses RPC to send a request to the server where that file is stored. The RPC server on that remote machine processes the request and sends the data back. When you encounter the “RPC Server is Unavailable” error, it means this essential communication line has been severed. The client (your computer) cannot establish a connection with the server that houses the resource or service it needs. This failure can manifest in various ways, including error messages in specific programs, an inability to browse network locations, or failures when trying to use networked printers.

The error is rarely a sign of hardware failure but is almost always related to software or configuration issues. It can occur in different contexts: you might see it when trying to connect to a domain on a corporate network, when using Microsoft Management Console (MMC) snap-ins to administer another computer, or when certain system services try to interact with each other locally. The root cause can range from a temporarily stopped service to incorrect firewall rules or deeper network stack corruption. Understanding that RPC is a core dependency for many Windows functions is the first step in appreciating why this error can have such wide-ranging effects.

Primary Symptoms and Initial Checks

Before diving into advanced solutions, it’s crucial to confirm the error and perform some basic checks. The most obvious symptom is an explicit error dialog box stating “The RPC server is unavailable” or “RPC server is not available.” Other symptoms include being unable to see other computers in your Network folder, receiving “access denied” errors when you previously had access, or specific applications failing to start with network-related errors. A useful first diagnostic step is to check if the problem is isolated to your machine or affects others on the same network. Try accessing the same network resource from a different computer. If the other computer succeeds, the issue is likely local to your PC. If it also fails, the problem may lie with the target server or a network-wide configuration. Next, perform a basic network connectivity test by opening Command Prompt and pinging the IP address of the server or computer you’re trying to reach using the command ping [IP address]. If the ping fails entirely, you have a broader network connectivity problem that must be resolved first.

Step-by-Step Solutions to Fix the RPC Error

Resolving the “RPC Server is Unavailable” error effectively requires a logical, step-by-step approach. Begin with the simplest and least intrusive solutions before progressing to more complex system modifications. This method ensures you don’t make unnecessary changes to your system while increasing your chances of a quick fix.

Solution 1: Restart Your Computer and Target Devices

It may seem trivial, but restarting your computer and the device you’re trying to connect to (like a file server or network printer) is the most effective first step. A restart can clear temporary software glitches, reset network adapters, and reload all critical system services, including the RPC services themselves. Often, a service may have entered a hung state or failed to start correctly after a Windows update or a sudden system crash. A fresh boot cycle forces all components to reinitialize from a clean state. After the restart, attempt the action that caused the error again to see if the issue persists. If the problem is with a network resource, ensure that the remote computer or server is also fully powered on and has completed its startup sequence before testing.

Solution 2: Verify and Restart Critical RPC Services

If a restart doesn’t work, the next step is to manually check the status of the Windows services responsible for RPC functionality. These services should always be running. To check them, press Windows Key + R, type services.msc, and press Enter. In the Services window, locate and examine the following two services:

Remote Procedure Call (RPC): This is the core service. Its Startup Type must be set to Automatic and its Status must be Running. This service cannot be stopped manually from here, which is normal.
RPC Endpoint Mapper: This service resolves RPC interfaces to specific port numbers. Its Startup Type should also be Automatic and its Status should be Running.

If the RPC Endpoint Mapper is stopped, right-click on it and select Start. If its Startup Type is not set to Automatic, right-click, select Properties, change the Startup type to Automatic, click Apply, and then Start. After making any changes, close the Services window and test if the error is resolved.

Solution 3: Configure Windows Firewall for RPC

The Windows Defender Firewall (or a third-party firewall) can block the specific network ports and protocols that RPC communication requires. It’s essential to ensure that the firewall is not interfering. First, check if temporarily disabling the firewall resolves the issue. Go to Settings > Update & Security > Windows Security > Firewall & network protection. Click on your active network profile (Domain, Private, or Public) and toggle the “Microsoft Defender Firewall” switch to Off. Warning: Only do this temporarily for testing purposes and ensure you are on a trusted network. Immediately test your network connection. If it works, the firewall is the culprit, and you need to add the proper rules instead of leaving it disabled.

To create the proper firewall rule, re-enable the firewall and navigate to “Advanced settings” in the Firewall & network protection page. In the Windows Defender Firewall with Advanced Security window, click on Inbound Rules in the left pane, then click New Rule… in the right pane. Create a rule to allow TCP port 135, which is the primary port used by the RPC Endpoint Mapper. You can also create rules for the dynamic range of ports (often 49152-65535) that RPC uses for subsequent communication, though allowing “Remote Assistance” and “Remote Desktop” through the firewall’s basic interface often handles this.

Solution 4: Reset the Network Stack and Check DNS

Corrupted network configuration files in Windows can break RPC communication. Resetting the network stack rebuilds these core components. Open Command Prompt as an Administrator (search for “cmd,” right-click it, and select “Run as administrator”) and run the following sequence of commands, pressing Enter after each:

netsh winsock reset
netsh int ip reset
ipconfig /release
ipconfig /renew
ipconfig /flushdns

The winsock reset command resets the Windows Sockets API catalog to a clean state. The int ip reset command resets TCP/IP settings. The ipconfig commands release and renew your IP address and clear the DNS resolver cache. After running these, restart your computer for the changes to take full effect.

Incorrect DNS (Domain Name System) settings can also prevent your computer from correctly resolving the name of the RPC server to its IP address. Ensure your network adapter is configured to obtain DNS server addresses automatically from your router, unless you use specific static DNS servers like Google’s (8.8.8.8, 8.8.4.4). You can check this in Settings > Network & Internet > Change adapter options, right-click your adapter, select Properties, double-click “Internet Protocol Version 4 (TCP/IPv4),” and verify the settings.

Solution 5: Check Network Profile and Sharing Settings

Windows uses different firewall and discovery rules based on your assigned network profile: Private, Public, or Domain. The “Public” profile is the most restrictive and can block the necessary discovery protocols that RPC relies on for locating services. Ensure your computer is set to the correct profile. Go to Settings > Network & Internet > Status. Click on “Properties” under your active connection. If the network profile is set to “Public,” change it to “Private” if you are on a trusted home or office network. This change enables Network Discovery and File and Printer Sharing, which are often prerequisites for RPC-based network operations.

Next, verify that Network Discovery and File and Printer Sharing are turned on. In the same Status page, click on “Sharing options.” In the Network and Sharing Center, ensure that for your current private network profile, the following are enabled: Turn on network discovery and Turn on file and printer sharing. These settings allow your computer to find other devices on the network and allow other devices to find it, which is essential for RPC to function correctly in a peer-to-peer or client-server environment.

Advanced Troubleshooting Techniques

If the standard solutions have not resolved the issue, the problem may be more deeply rooted in system configuration, policy settings, or component corruption. These advanced steps require more care but can resolve stubborn cases of the RPC error.

Verify DCOM Permissions and System Integrity

The Distributed Component Object Model (DCOM) is a technology built on top of RPC. Incorrect DCOM permissions can cause RPC failures, especially in domain environments or when specific applications are involved. Checking these permissions is complex and typically more relevant for system administrators. However, a simpler related step is to run the System File Checker (SFC) tool. This built-in utility scans for and repairs corrupted or missing Windows system files that could be affecting RPC components. Open an Administrator Command Prompt and run: sfc /scannow. Let the scan complete (it can take 10-15 minutes). If it finds and repairs any corruption, restart your computer and test again.

Review Event Viewer Logs for Clues

The Windows Event Viewer is a powerful diagnostic tool that logs detailed system errors and warnings. When the RPC error occurs, related events are often recorded here, providing specific error codes or pointing to failing sub-components. To open Event Viewer, press Windows Key + R, type eventvwr.msc, and press Enter. Navigate to Windows Logs > System. Look for error or warning events with a source related to “RPC,” “DCOM,” “Service Control Manager,” or the specific application that failed. Click on an event to see its details. The “General” tab provides a description, and the “Details” tab may contain technical error codes. Searching for these codes online can lead you to very specific fixes that standard guides do not cover.

Clean Boot to Isolate Software Conflicts

A clean boot starts Windows with a minimal set of drivers and startup programs. This process helps determine if background programs are interfering with RPC services. To perform a clean boot, type msconfig in the Run dialog box. In the System Configuration window, go to the Services tab, check “Hide all Microsoft services,” and then click Disable all. Next, go to the Startup tab and click “Open Task Manager.” In Task Manager, disable all startup items. Close Task Manager, click OK in System Configuration, and restart. After the clean boot, test for the RPC error. If the error is gone, a background service or startup item is the cause. You can then systematically re-enable items in groups (half at a time) in msconfig, restarting and testing each time, to pinpoint the conflicting software.

Pro Tips for Preventing RPC Errors

Prevention is always better than troubleshooting. By adopting a few best practices, you can minimize the chances of encountering the “RPC Server is Unavailable” error in the future.

Keep Windows Updated: Regularly install Windows updates. Microsoft often releases patches for security vulnerabilities and bugs in core components like RPC and networking services. Use automatic updates or check manually in Settings > Update & Security.
Maintain Antivirus Software Wisely: Ensure your antivirus software is up to date, but also be aware that overzealous security suites can sometimes block legitimate RPC traffic. Check your antivirus logs if network issues arise and consider temporarily disabling its network filtering for testing (on a trusted network).
Use Consistent Network Profiles: Avoid frequently switching your computer between different networks (e.g., from a domain at work to a public Wi-Fi). If you must, be mindful that services dependent on the domain may not function on the public network. Consider using a VPN for consistent remote access.
Document Network Configurations: For home or small office networks, keep a simple record of static IP addresses, computer names, and key settings. This makes it much easier to restore correct configurations if they are accidentally changed.
Avoid Tinkering with Advanced Services: Unless you are certain of the consequences, avoid manually stopping, disabling, or changing the properties of core Windows services, especially those related to RPC, DCOM, and networking.

Frequently Asked Questions

Is the “RPC Server is Unavailable” error a security risk?

The error itself is not a virus or direct security threat; it is a communication failure. However, the underlying cause could be related to security software blocking traffic or, in rarer cases, a malware infection that has damaged system files or is blocking legitimate services. It’s always a good practice to run a full system scan with your antivirus and an anti-malware tool like Malwarebytes if you suspect an infection.

Can this error occur on Windows 11 or older versions like Windows 7?

Yes, absolutely. The RPC protocol is a fundamental part of all modern Windows operating systems. The “RPC Server is Unavailable” error can and does occur in Windows 11, Windows 10, Windows 8, and Windows 7. The core troubleshooting steps—checking services, firewall, and network settings—are very similar across these versions, though the exact path to certain settings menus may differ slightly.

I’m getting the error only with one specific program. What should I do?

When the error is application-specific, it points to a problem with how that program is configured to use RPC, rather than a system-wide RPC failure. First, check the program’s documentation or support site for any known issues with RPC or network connectivity. Try running the program as an administrator (right-click the shortcut and select “Run as administrator”). You can also try repairing or reinstalling the application, as its installation may have become corrupted.

What is the difference between RPC and RPC Endpoint Mapper?

Think of the core Remote Procedure Call (RPC) service as the engine that makes the communication protocol work. The RPC Endpoint Mapper is a crucial component of that engine. When an RPC client wants to talk to a server, it first contacts the server’s RPC Endpoint Mapper on a well-known port (TCP 135). The mapper tells the client which specific, dynamic port the actual service it needs is listening on. Both services must be running for RPC communication to succeed.

After trying everything, the error remains. What are my last resort options?

If all else fails, you have two primary nuclear options, which should be used in order. First, perform a Windows Reset. Go to Settings > Update & Security > Recovery and select “Reset this PC.” Choose “Keep my files,” which will reinstall Windows while preserving your personal data but removing all applications and settings. This fixes deep system corruption. The final, most complete option is a clean installation of Windows from USB media, which erases everything on the system drive and installs a fresh copy of the OS. Back up all data before proceeding with either option.

Conclusion

Resolving the “RPC Server is Unavailable” error in Windows is a systematic process of elimination that progresses from simple restarts to advanced system checks. The key is to start with the fundamentals: ensuring the essential RPC and RPC Endpoint Mapper services are running, verifying that the Windows Firewall is not blocking necessary communication, and resetting the network stack to clear any corruption. For persistent issues, tools like the Event Viewer and the clean boot procedure are invaluable for isolating software conflicts and uncovering specific error codes. By understanding the critical role RPC plays in network and inter-process communication, you can approach this error not as an insurmountable problem, but as a manageable configuration or software issue. Implementing the pro tips for system maintenance will further help in preventing its recurrence, ensuring stable and reliable connectivity for your Windows-based activities.

Recommended For You