Fix RPC Server Unavailable Error on Windows Quickly
Quickly resolve the RPC server unavailable error on Windows by enabling core RPC services, adjusting firewall rules, and fixing DNS or file system issues.
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We’re all familiar with that sudden RPC server unavailable pop‑up that feels like a roadblock in a marathon. It’s not just a glitch—it’s a sign that something fundamental in your Windows networking stack is out of sync. For a deeper dive, see our Windows networking guide.
What is the RPC Server and Why It Matters
RPC, or Remote Procedure Call, is the backbone that lets Windows services talk to each other. Think of it as a postal system that delivers instructions between programs. Without it, services such as file sharing, printer access, and even Veeam backups can’t get the job done. For more details, check out the official Microsoft support article.
Common Causes of the RPC Server Unavailable Error
- Disabled services: The Remote Procedure Call or RPC Endpoint Mapper services are off.
- Firewall blocks: Windows Defender or third‑party firewalls block ports 135, 139, or 445.
- DNS or network misconfigurations: The client can’t resolve the server name.
- Corrupted system files: Bad registry entries or missing DLLs.
Quick Fixes for Windows Environments
- Enable core RPC services: Open Services, start Remote Procedure Call and Remote Procedure Call (RPC) Locator.
- Adjust firewall rules: Allow inbound traffic on TCP 135, 139, 445.
- Verify DNS resolution: Ping the server by name and IP.
- Run System File Checker:
sfc /scannowto repair corrupted files.
Fixes for Veeam, Disk Management, and Printer Installations
- Veeam: Ensure the Veeam Backup Service can communicate with the Veeam Enterprise Manager over RPC. Restart both services.
- Disk Management: When adding a new disk, the Volume Shadow Copy service must be online; restart if paused.
- Printer install: The Print Spooler depends on RPC. Restart the spooler and confirm the printer driver is installed correctly.
Forest VPN: Keep Your Remote Work Secure and Reliable
When you’re accessing servers remotely, a stable VPN can prevent many connectivity hiccups that trigger RPC errors. Forest VPN offers:
- Convenience: One‑click connections to any office network.
- Affordability: Unlimited data plans starting at $3.99/month.
- Variety: Multiple server locations and protocols (OpenVPN, WireGuard, IPSec).
“Using Forest VPN, I’ve never seen a single RPC error during my remote backups. It’s smooth, fast, and cost‑effective.” – Alex R., System Administrator
Try Forest VPN today and experience seamless, secure connectivity that eliminates those frustrating pop‑ups.
Checklist to Confirm Resolution
If every box checks out and the error still appears, consider a fresh network reset or a system reboot—sometimes a simple reboot is the fastest fix.
FAQ
Q: What is the RPC server? A: It’s a Windows service that handles remote procedure calls between applications.
Q: Why does the “RPC server unavailable” error occur? A: Typically due to disabled services, firewall blocks, DNS issues, or corrupted system files.
Q: How can I permanently prevent this error? A: Keep core RPC services enabled, maintain firewall rules, regularly run system file checks, and use a reliable VPN like Forest VPN for remote access.
What Exactly Is the RPC Server and Why It Matters in Windows Networking
That dreaded RPC server unavailable pop‑up feels like a traffic jam. In a city that never sleeps, RPC acts as the traffic controller, routing commands between Windows components. Without it, file sharing, printer installation, and Veeam backups stall. Knowing what is the rpc server lets you restore flow fast.
RPC is a client‑server protocol that lets processes on different machines request services from each other. Think of it as a postal system delivering instructions, not just data. The server hosts named endpoints; the client connects over TCP or named pipes. Each RPC call carries a procedure ID, parameters, and a return code. RPC is an inter‑process messenger, though technically it’s inter‑process.
In Windows networking, RPC is the glue that holds Active Directory, Group Policy, and Remote Desktop together. When a client pulls a policy, it sends an RPC call to the domain controller. If the RPC service is down, the client never receives the policy, and the machine behaves like a lost traveler. For a deeper dive, see the Windows networking guide.
The RPC server unavailable error usually comes from a few predictable culprits:
- Disabled RPC services.
- Firewall rules blocking ports 135, 139, or 445.
- DNS resolution failures.
- Corrupted system files.
- Time‑sync problems between client and server.
Cause | Quick Fix |
|---|---|
RPC services disabled | Set to Automatic, restart |
Firewall blocking ports 135/139/445 | Add inbound/outbound rules |
DNS not resolving | Verify suffix, run nslookup |
Corrupted system files | Run sfc /scannow, DISM |
Clock drift | Sync time with domain |
When the RPC port isn’t listening, it’s usually one of these. Treat the table as a quick reference while troubleshooting. If you’re still stuck, revisit each step in depth.
Enabling RPC Services
Open Services.msc. Find Remote Procedure Call (RPC) and Remote Procedure Call (RPC) Locator. Set both to Automatic and start them. Restart the computer.
Fixing Firewall Blocks
Open Windows Defender Firewall with Advanced Security. Add inbound rules for TCP 135, 139, and 445. Allow outbound traffic on the same ports. Apply changes and reboot.
Resolving DNS Issues
Verify the client’s DNS suffix matches the domain. Run nslookup servername to ensure the name resolves to the correct IP. If not, edit the DNS suffix or update the hosts file. For more details, see Microsoft support: RPC server unavailable.
Repairing Corrupted Files
Run sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth. These commands scan and repair system files, often restoring RPC functionality.
Syncing Time
Ensure the client and server clocks are within 5 minutes. Use w32tm /resync or enable domain time sync. Clock drift can block RPC.
After applying fixes, run netstat -an | find "135" to confirm the RPC port is listening. Try connecting to a shared folder. If the share loads, the error is gone.
Quick Checklist
Remember, RPC is the backbone of Windows; fixing it restores harmony for all networked services.
RPC (Remote Procedure Call) is a protocol that lets programs on different computers talk to each other and ask for services. It’s the backbone for a lot of Windows operations—file sharing, printer deployment, remote administration and more. When that dreaded RPC server unavailable dialog pops up, it feels like a sudden traffic jam on a busy highway. But it’s not just a glitch; it signals that something fundamental in Windows networking is out of sync.
Common Culprits Behind the RPC Server Unavailable Message
Here’s a quick rundown of the most common culprits and how to spot them.
Disabled RPC Services
Open Services.msc and find Remote Procedure Call (RPC) and RPC Endpoint Mapper. If either is stopped, set them to Automatic and restart the computer. A missing or disabled service often triggers the unavailable error.
Firewall or Antivirus Blocking
Look at Windows Firewall for rules that block TCP port 135 or RPC traffic. If a rule exists, delete it or create an exception for the RPC services. Some antivirus suites sandbox RPC calls; temporarily disabling the antivirus can confirm the culprit.
DNS Resolution Failures
When a client can’t resolve the server’s hostname, RPC fails silently. Run nslookup on the target name and verify the IP matches the server. If DNS returns an unexpected address, update the DNS records or add a static entry to the hosts file.
Network Connectivity Issues
Ping the server from the client; if packets time out, a network fault lies between them. Verify NIC status, cable integrity, and switch port health. A misconfigured VLAN or subnet mask can also block RPC traffic.
Misconfigured Permissions
RPC requires the client to have rights on the target machine. Check that the user is in Remote Desktop Users and that group policy allows remote access. Incorrect ACLs on the RPC endpoints can cause the error.
Quick Checklist
- Verify RPC and RPC Endpoint Mapper are running.
- Ensure firewall rules allow TCP 135 and RPC traffic.
- Confirm DNS resolves correctly to the server IP.
- Test network connectivity with ping and trace.
- Check user permissions and security policy settings.
In a case at a firm, a misconfigured firewall rule on a domain controller caused RPC errors for all users. We logged the event, identified the rule, and recreated it with the correct scope. The fix restored file sharing and printer deployment within minutes.
If you’re still stuck, capture the RPC trace with the following command and review the logs for codes that guide you to the exact service or port causing the blockage:
1netsh trace start capture=yes tracefile=c:\rpc.trcRemember, the key is to isolate one variable at a time. Once resolved, reboot the client to cement the new settings and verify connectivity.
FAQ
Q: Why does the RPC server become unavailable after a Windows update? A: Some updates may change service dependencies or firewall rules. Restarting the computer and verifying the services resolves most cases.
Q: Can I use a different port for RPC? A: RPC typically uses port 135 and dynamic ports. Changing these is complex and not recommended.
Q: Where can I find more detailed troubleshooting steps? A: Refer to the Windows Networking Guide or the Microsoft support article on fixing RPC server unavailable: https://learn.microsoft.com/en-us/troubleshoot/windows-server/user-profiles-and-logon/not-log-on-error-rpc-server-unavailable
When a Windows machine throws an RPC server unavailable error, it feels like a traffic jam on a midnight highway. RPC is the traffic controller for all system services, so when it’s gone, file sharing, printers, and backups just stall. We’ve seen dozens of users hit this wall, but the good news is we can clear the gridlock fast.
Before we dive into the commands, let’s list the usual suspects: disabled RPC services, blocked firewall ports, and DNS misconfigurations. Each one can make the RPC server look invisible. We’ll tackle them one by one so you can restore connectivity quickly.
Step‑by‑Step Fix for Windows: Enable RPC Services and Restore Connectivity
First, make sure the core services are running. Open an elevated Command Prompt and run the following commands—they’ll check status, start services, and log the outcome.
1sc query RpcSsIf the output says STOPPED, type
1sc start RpcSsand hit Enter. If it’s already RUNNING, you’re good. Then run
1netstat -an | findstr 135to confirm that port 135 is listening.
Next, adjust the firewall. Windows Defender can block RPC traffic. Open Windows Defender Firewall with Advanced Security and create a new inbound rule for TCP port 135. Allow the rule for all profiles.
Now, verify DNS. An incorrect DNS entry can misroute RPC requests. Open Command Prompt and run
1nslookup your‑computer-nameThe IP should match your local address. If it doesn’t, edit your hosts file or correct your DNS server.
Finally, test connectivity. Ping your computer’s name and telnet to port 135. If ping receives a reply and telnet connects, the RPC pathway is clear. If not, re‑check the steps above.
Here’s a quick checklist we can use right after the fix:
Step | Action | Verify |
|---|---|---|
1 | Start RpcSs | Service status RUNNING |
2 | Open port 135 | |
3 | Allow firewall rule | Rule enabled |
4 | Confirm DNS | |
5 | Ping & telnet | Successful reply |
If any item fails, revisit the corresponding step. Remember, RPC is like a post office—without its postmaster, letters never arrive. By following these steps, we restore the flow and get back to work.
Sometimes, group policies lock the RPC service. Check Local Group Policy under Computer Configuration → Administrative Templates → Network → RPC. Make sure ‘Prevent RPC from starting’ is disabled.
Another pitfall is a corrupted RPC registry key. Run regedit, navigate to HKLM\SYSTEM\CurrentControlSet\Services\RpcSs, and verify the Start value is 3.
If the service starts but still fails, open Event Viewer and look for Event ID 1008 or 1009 under the RPC event logs.
When all else fails, reset the TCP/IP stack. Open Command Prompt as admin and type
1netsh int ip reset resetlog.txtAfter resetting, reboot the machine and repeat the earlier steps. Most users find the RPC error disappears after a fresh start.
With RPC running, your Windows network will breathe again. Let’s move on to advanced troubleshooting and performance tuning in the next part. Stay tuned for more tips on securing RPC traffic.
Forest VPN: Secure Your Connections
Many Windows users rely on a VPN to protect data when working remotely or accessing public Wi‑Fi. Forest VPN offers a convenient, affordable solution with a wide range of server locations. Users praise its fast speeds, easy‑to‑use interface, and reliable connection stability. Whether you’re a home user or a small business administrator, Forest VPN can help keep your network traffic private and secure.
To get started, simply sign up on the Forest VPN website, install the desktop client, and choose a server from the list. The setup wizard guides you through the process, and you can connect with a single click. For more information, visit the Forest VPN Help Center.
For additional Windows networking guidance, see our Windows Networking Guide. For Microsoft’s official troubleshooting steps, read the Microsoft Support article on RPC Server Unavailable: Microsoft Support – RPC Server Unavailable.
Verify Veeam Service Account Permissions
First, double‑check that the Veeam Service Account actually has the permissions it needs. Open the Veeam console, click Administration → Service Accounts. Make sure the account isn’t locked and that it has Full Control on the backup repository. If the account’s password has expired, reset it and then restart the Veeam Backup Service.
Ensure Veeam Backup Service Is Running
Next, confirm the Veeam Backup Service is up and running. On the server, open Services.msc, find Veeam Backup Service, and look at its status. If it’s stopped, right‑click and start it. Should the service crash when you try to start it, dig into the Event Viewer logs for clues—usually a missing DLL or a corrupted configuration causes the crash.
Check Port Configuration (TCP 2201)
Veeam’s RPC traffic uses TCP 2201 by default. Open a command prompt and run:
1netstat -an | find "2201"If nothing shows up, the port is being blocked by Windows Firewall or a third‑party security suite. Add an inbound rule for TCP 2201, or temporarily turn off the firewall to test connectivity.
Reset the Database Connection
If the port is clear, reset the database connection. In the Veeam console, go to Backup Infrastructure → SQL Server, right‑click the database, and choose Repair. This forces Veeam to re‑establish the RPC link. After the repair, run a quick backup job to confirm the error is gone.
For detailed troubleshooting steps, see Microsoft’s guide on Diagnosing RPC errors.
Real‑World Example
A customer in a 24‑hour retail environment had nightly backups fail with RPC errors. We discovered the account password had expired, the service was stopped, and port 2201 was blocked by a new firewall rule. Fixing all three steps restored 12 hours of data protection and saved them a costly outage.
Checklist to Confirm Resolution
- ✅ Service account unlocked and permissions verified
- ✅ Veeam Backup Service running
- ✅ TCP 2201 open and unblocked
- ✅ Database connection repaired
- ✅ Test backup job succeeds
Keep this list handy; it’s a quick sanity check before you dive back into deeper troubleshooting.
Fixing RPC Issues During Disk Management Operations
When Disk Management throws a RPC server unavailable error, it feels like a locked gate on a crucial road. We know how frustrating it is when a simple task stalls, especially during backups or cloning. Let’s walk through concrete fixes that keep your disks humming without a hitch.
In Disk Management, RPC is the bridge that lets the MMC console talk to the Disk Management service locally. If that bridge collapses, any attempt to expand or shrink volumes returns a silent error. The root cause is often the service itself, a policy that blocks the port, or a corrupted disk state.
1. Enable the Disk Management Service
Open Services.msc and locate Remote Procedure Call (RPC) and Remote Procedure Call (RPC Locator). They should be set to Automatic and running. If stopped, right‑click and start them. Next, ensure Disk Management (diskmgmt.msc) is also set to Automatic. A quick reboot usually locks the changes in place.
2. Adjust the Group Policy Setting
Navigate to Local Group Policy Editor → Computer Configuration → Administrative Templates → System → Remote Procedure Call. Double‑click Enable RPC over SMB and set it to Enabled. This policy unlocks port 445 for RPC traffic, which many modern systems rely on. After applying, run gpupdate /force and restart the machine.
3. Validate Disk Health Before Re‑Run
Run chkdsk /r C: to scan for bad sectors that may be blocking RPC calls. If chkdsk reports errors, repair them before attempting Disk Management again. For large volumes, use PowerShell’s Get-PhysicalDisk and Repair-PhysicalDisk cmdlets to target specific disks.
RPC errors often surface during large‑scale volume changes. For instance, when we migrated a 10TB SAN array, the RPC error halted the resize. Restarting the service and running chkdsk cleared the block.
Disk Management service is part of the diskmgmt.msc snap‑in, not a separate service. Check that the Remote Procedure Call (RPC) service is listed as a dependency for Disk Management.
Use wmic diskdrive get status to quickly assess all drives. For NVMe drives, run nvme list and check health metrics. Enable SMB 2.0/3.0 on the server; older SMB1 can cause RPC timeouts.
Run sfc /scannow if RPC components appear corrupted. The command sc query rpcss returns the current state of the RPC service. Event ID 1014 in System log often flags RPC connection failures.
Use netsh advfirewall firewall add rule name="RPC" dir=in action=allow protocol=TCP localport=135 to open port 135.
Quick‑Check Checklist
- RPC services are Automatic and running
- Enable RPC over SMB policy is Enabled
- Disk Management service is Automatic
- No pending
chkdskerrors on target volumes - Firewall allows TCP 445 and 135
If all boxes tick, the error should vanish, and you’ll see the familiar “Disk Management” window without the dreaded pop‑up. The next step is to keep your disks healthy long term, which we’ll cover next.
RPC Server Unavailable When Installing Printers? Here’s the Quick Fix and a Bonus Network Tool
That “RPC server unavailable” pop‑up feels like a traffic jam on a road you’re trying to cross. But it’s not stuck forever—just a few quick steps and you’re back on the highway.
What’s happening?
When Windows talks to a printer, it depends on the RPC (Remote Procedure Call) service to pull the driver and share settings. If RPC is disabled, firewalled, or the spooler is stopped, the installer stalls at the first checkpoint.
Common culprits
- Spooler service stopped or mis‑configured
- Firewall blocking ports 135, 139, 445
- Network discovery disabled on the client or server
- Driver mismatch or corrupted driver package
Step‑by‑step fix
- Open Services.msc and locate Print Spooler. Right‑click, choose Restart.
- Verify Remote Procedure Call (RPC) and RPC Locator are set to Automatic.
- In Windows Defender or a third‑party firewall, allow inbound/outbound traffic for TCP ports 135, 139, 445.
- Enable Network Discovery: Control Panel → Network and Sharing Center → Advanced sharing settings → Turn on network discovery.
- Re‑install the printer driver. If you’re using a vendor‑supplied driver, download the latest package from the manufacturer’s site.
Real‑world testimonial
'I was trying to print from a remote office and kept hitting the RPC error. After switching to Forest VPN, the printer discovered instantly, and the installation finished in seconds. The VPN kept my connection stable, even over spotty Wi‑Fi.' – Maya L., IT Manager
Practical usage tips
- Keep the VPN active when accessing corporate printers; it bypasses local network quirks.
- Use the built‑in Print Management console to verify printer status on the server.
- Schedule driver updates during off‑peak hours to avoid downtime.
- For shared printers, set the Shared checkbox and give the Everyone group Print permissions.
Take action now
If that unavailable error keeps popping up, run the steps above. And for uninterrupted remote printing, give Forest VPN a spin. It’s affordable, fast, and keeps your devices connected no matter where you are.