Fix 0X00000842: Server service not started

Been there. You're trying to access a network share or maybe just checking services.msc and that 0X00000842 pops up. The Server service won't start, and nothing else works until it does. Let's cut the crap and get it running.

Quick fix — restart the Server service

Open an admin command prompt or PowerShell and run these two commands. No reboot needed in most cases.

net stop lanmanserver /y
net start lanmanserver

The /y flag forces dependent services (like the Browser service) to stop too. Then the second line starts the Server service back up. If it starts fine, you're done. Test your network shares.

If it fails with "System error 5 has occurred" or "Access denied", you're not running as admin. Right-click the prompt, pick Run as administrator, try again.

If the service won't start — check dependencies

The Server service depends on three things: RPCSS (Remote Procedure Call), SamSS (Security Accounts Manager), and Srv2 (SMB 2.0 driver). If any of those are broken, the Server service sits there and refuses.

Open services.msc and find Server in the list.
Double-click it and go to the Dependencies tab.
You'll see Remote Procedure Call (RPC), Security Accounts Manager, and SMB 2.0 Protocol listed.
Check each of those services are running. If RPCSS isn't running, you've got bigger problems — usually a corrupted system file or aggressive security software.

The culprit here is almost always RPCSS being set to Manual instead of Automatic. RPCSS must start at boot. Check its startup type: it should be Automatic. If it's Manual or Disabled, change it to Automatic and reboot.

When dependencies are fine — check the registry

Sometimes the service is set to disabled in the registry itself. This happens after a botched group policy or a security cleanup script gone wrong.

reg query HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer /v Start

You want the Start value to be 2 (Automatic). If it's 4 (Disabled) or 3 (Manual), fix it:

reg add HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer /v Start /t REG_DWORD /d 2 /f
net start lanmanserver

Don't bother with sc config here — registry edits are more reliable when the service state is corrupted.

Less common variations

SMB 1.0/CIFS File Sharing Support disabled

On Windows 10/11 and Server 2016+, SMB 1.0 is off by default. That's fine — SMB 2.0 handles everything. But if someone manually disabled all SMB features via Windows Features, the Server service won't start. Go to Control Panel > Programs and Features > Turn Windows features on or off. Make sure SMB 1.0/CIFS File Sharing Support is unchecked (you don't want that old insecure junk) but SMB Direct and SMB Mapping are fine. The Server service only needs SMB 2.0, which is baked into the OS and can't be removed.

Third-party security software blocking the service

I've seen this on servers with CrowdStrike, SentinelOne, or McAfee installed. They can block the Server service from starting because they think it's suspicious. Check your antivirus logs for blocks on lanmanserver.exe. Temporarily disable the AV and try the net start command again. If it works, add an exception for that process.

Corrupted service DLL

The Server service runs from %SystemRoot%\System32\srvsvc.dll. If that file is missing or corrupted, re-register it:

regsvr32 srvsvc.dll

If that fails, run an SFC scan:

sfc /scannow

That'll fix any system file corruption. After SFC finishes, reboot and try starting the service again.

Why this happens in the first place

Most of the time, the Server service gets stuck because of a failed update or a power outage that left the service in a bad state. The service control manager can't start it because the previous stop didn't complete cleanly. That's why the net stop /y trick works so well — it force-kills any hung processes and resets the state.

Second most common cause: group policy. If your domain pushes a policy that sets the Server service startup type to Disabled (yes, some admins do this thinking it's a security measure), you'll see this error. Check gpedit.msc or rsop.msc under Computer Configuration > Windows Settings > Security Settings > System Services. The Server service should be set to Automatic.

Prevention

Stop the bleeding before it starts. Three things:

Never set the Server service to Disabled. Even if you're trying to harden a box, there are better ways to lock down SMB (like firewall rules or SMB signing).
After Windows updates, check that the Server service is still running. I automate this with a simple scheduled task that runs sc query lanmanserver and alerts if it's not running.
Monitor Event IDs 7026 and 7000 in the System log. Those mean a service failed to start. Catch it early, fix it before users complain.

That's it. You should have your Server service running again. If not, check the SMB 1.0 feature or the security software. I've never seen this error persist past those steps.