Fix STATUS_CTX_SHADOW_NOT_RUNNING 0XC00A0036 Quick

Quick answer: Restart the Remote Desktop Shadow service. Open Services.msc, find "Remote Desktop Services" (TermService), right-click and restart it. Then re-attempt the shadow connection.

What causes STATUS_CTX_SHADOW_NOT_RUNNING (0XC00A0036)?

This error shows up when you're running Remote Desktop Services Manager on Windows Server (typically 2012 R2, 2016, or 2019) and try to shadow a user session — right-click a session, select Remote Control, and boom, you get the 0XC00A0036 error. The shadow component literally isn't listening. I've seen this most often after Windows updates or when the TermService gets stopped by a security policy, like after a server reboot where the service didn't start properly.

The shadow service depends on the Remote Desktop Services service (TermService). If that service isn't running, or if its shadow sub-component (the actual "Remote Desktop Shadow" part) is disabled, you can't initiate a remote control session. It's not a permissions issue — it's a service state issue.

How to fix it (main fix)

1. Press Windows + R, type services.msc, hit Enter. This opens the Services console.
2. Scroll down to Remote Desktop Services. Its service name is TermService. The display name might also show "Remote Desktop Services (TermService)".
3. Check its status. If it's not "Running", right-click it and select Start. Wait 5-10 seconds.
4. If it is already running, right-click it and select Restart. Confirm any prompts. This stops and restarts the service cleanly. After restarting, you'll see the status change to "Stopped" briefly, then back to "Running".
5. Open Remote Desktop Services Manager again. Right-click the user session you want to shadow, choose Remote Control. The error should be gone now.

Alternative fixes if the main one doesn't work

If restarting TermService didn't fix it, here's what else to check:

1. Make sure the Shadow service isn't disabled

There's also a service called Remote Desktop Shadow Service (display name: Remote Desktop Services Shadow Service, service name: RDShadow). This is the actual shadow component. On some systems, it might be set to Manual or Disabled. Here's how to check:

1. In Services.msc, find "Remote Desktop Services Shadow Service".
2. If its startup type is Disabled, double-click it, set Startup type to Manual, click Apply, then click Start to run it now.
3. If it's already Manual or Automatic, just start it if it's stopped.
4. After that, restart the main TermService again (right-click Remote Desktop Services, Restart).

2. Check Group Policy: "Set rules for remote control of Remote Desktop Services user sessions"

A restrictive Group Policy can block shadow sessions entirely. If you're on a domain, your admin might have locked this down. To check locally:

1. Press Windows + R, type gpedit.msc, hit Enter.
2. Go to: Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Connections.
3. Find the policy "Set rules for remote control of Remote Desktop Services user sessions".
4. If it's set to Enabled, make sure the drop-down says "Full Control without user's permission" or "Full Control with user's permission" (depending on your needs). If set to "Disabled" or "Not Configured", shadowing might still work, but the policy can override. Set it to "Not Configured" or a permissive value.
5. Close Group Policy Editor, run gpupdate /force in Command Prompt (as admin), then restart TermService.

3. Re-register the shadow component

If the service files are corrupted, re-register the DLL. Open Command Prompt as Administrator and run:

regsvr32.exe %systemroot%\system32\rdshadow.dll

You should see a success message: "DllRegisterServer in rdshadow.dll succeeded." Then restart TermService.

4. Verify the user session is active

You can't shadow a disconnected session. In Remote Desktop Services Manager, make sure the session you're trying to shadow has a Status of "Active". If it's "Disconnected", shadowing won't work — you'll get a different error, but it's worth checking.

Prevention tip

After a Windows Update, always check the TermService and RDShadow service startup types. I've seen updates reset the RDShadow service to Disabled. To avoid this, set both services to Automatic startup type:

• Remote Desktop Services (TermService) — should already be Automatic.
• Remote Desktop Services Shadow Service (RDShadow) — set to Automatic.

Then after any reboot, run a quick test: open Remote Desktop Services Manager and try to shadow a test session. If it fails, you'll catch it before users complain.

That's it. The 0XC00A0036 error is almost always a service state issue. The fix is restarting the service or re-registering the DLL. You don't need to reinstall anything or dive into registry hacks.