Please wait for the System Event Notification Service: how to fix it

Applies to: Windows 11, Windows 10 and Windows Server 2016, 2019 and 2022, including Remote Desktop sessions. The same message also appears on older Windows 7 and Server 2008 R2 systems.

What the message means

The System Event Notification Service (SENS, service name SENS) passes system events to programs that have asked to hear about them. Microsoft lists three kinds: network connection changes, user logon events, and battery or AC power changes. Programs such as security software, VPN clients, backup agents, printer tools and Windows components subscribe to these notifications.

When you sign in, sign out or shut down, Windows waits while SENS delivers the notification. If a subscriber hangs, the screen shows “Please wait for the System Event Notification Service” until it times out or you restart. It’s most common on Remote Desktop servers when users sign out, but it can happen on a normal PC too.

Fix 1: Wait, then restart properly

Give it five to ten minutes. Microsoft’s developer documentation says that on Windows 7 and Server 2008 R2, a program has at most 3 minutes to respond to a logon notification before SENS cancels the call, so short delays often clear on their own.

If it’s still stuck:

• On your own PC: hold the power button for about 10 seconds to turn it off, wait a few seconds, then turn it on again. Anything you hadn’t saved is lost.
• On a virtual machine: use your hypervisor’s reset or restart option.
• On a server you can reach from another computer: open Command Prompt as administrator on that computer and run the command below, replacing SERVERNAME with the server’s name. Warn other signed-in users first, because /f closes their apps without saving.

shutdown /r /f /t 0 /m \\SERVERNAME

If the PC restarts normally and the message doesn’t come back, you can stop here. If it returns at every sign-in or sign-out, carry on with the fixes below.

Fix 2: Sign out a stuck Remote Desktop session

If only one user’s session is stuck on a server, you don’t need to restart the whole server.

1. Inside the stuck Remote Desktop window, press Ctrl + Alt + End (the Remote Desktop version of Ctrl + Alt + Del) and try Sign out or open Task Manager.
2. If that doesn’t respond, sign in to the server with another administrator account, open Task Manager, go to the Users tab, right-click the stuck user and select Sign off.
3. Or, from Command Prompt, list the sessions and log off the stuck one by its ID:

quser /server:SERVERNAME
logoff 3 /server:SERVERNAME

Replace 3 with the session ID shown by quser. Logging off a session ends all of its programs, so unsaved work in that session is lost. You need administrator rights (Full Control) to log off another user.

If the hang only ever happens over Remote Desktop, test with printer redirection turned off: in Remote Desktop Connection select Show Options, open the Local Resources tab and untick Printers. Redirected printer drivers are a frequent cause of slow sign-in and sign-out on session hosts. If that helps, update or replace the printer drivers on the server.

Fix 3: Check the SENS and COM+ Event System services

SENS depends on the COM+ Event System service (service name EventSystem). If either is stopped, disabled or set to the wrong startup type, notifications can stall.

1. Press Win + R, type services.msc and press Enter.
2. Double-click System Event Notification Service. Set Startup type to Automatic, select Start if it isn’t running, then select OK.
3. Do the same for COM+ Event System.

Or do it from Command Prompt opened as administrator (note the space after start=):

sc config EventSystem start= auto
sc config SENS start= auto
net start EventSystem
net start SENS

If a service won’t start, note the error message; it usually points to a damaged system file (Fix 6) or a security program blocking it (Fix 5). Other core services failing at the same time is a similar sign; see the Diagnostics Policy Service is not running for the same kind of service checks.

Fix 4: Install updates and finish pending restarts

A half-installed update can leave services waiting at sign-out or shutdown. Go to Settings > Windows Update, select Check for updates, install everything offered and restart. On a server, also install the latest cumulative update during a maintenance window.

If Windows then sits on an update screen for a long time, see Getting Windows ready, don’t turn off your computer before forcing it off.

Fix 5: Find the program that blocks sign-in or sign-out

Because the hang is caused by a program that listens for SENS notifications, the lasting fix is usually to update or remove that program. Two ways to find it:

Check Event Viewer. Press Win + X and select Event Viewer. Look around the time of the hang:

• Windows Logs > Application: warnings from the source Winlogon can name the notification subscriber that took too long, for example a Group Policy or session component.
• Windows Logs > System: errors from Service Control Manager such as event ID 7011 (a service timed out) or 7031 and 7034 (a service stopped unexpectedly) show which service is misbehaving.

Do a clean boot. Press Win + R, run msconfig, open the Services tab, tick Hide all Microsoft services and select Disable all. Then disable startup apps in Task Manager > Startup apps and restart. If sign-in and sign-out are now quick, turn the services back on in small groups until the delay returns. Antivirus and endpoint security agents, VPN clients, backup agents and printer utilities are the usual suspects. Undo the clean boot when you’re done by selecting Normal startup in msconfig.

Don’t do a clean boot on a production server without planning for it, because disabling third-party services can stop line-of-business software. If you suspect malware rather than a normal app, scan the PC with Microsoft Defender’s offline scan as well.

Fix 6: Repair Windows system files

Damaged system files can stop services from starting or responding. Open Command Prompt as administrator and run these two commands, one after the other:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

DISM can take a while and may pause at 20% or 62%; let it finish. Restart afterwards. If SFC reports that it couldn’t repair some files or can’t run at all, see Windows Resource Protection could not perform the requested operation.

Fix 7: “Windows could not connect to the System Event Notification Service”

A related message, “Windows could not connect to the System Event Notification Service service”, appears as a warning after sign-in. On affected PCs, standard (non-administrator) users may be unable to sign in at all while administrators can.

1. Sign in with an administrator account.
2. Check that both services are running (Fix 3).
3. Open Command Prompt as administrator, run the command below, then restart the PC.

netsh winsock reset

Resetting Winsock removes damaged network provider entries that some security and VPN programs install, and it’s a common fix for this variant. You may need to reinstall the VPN or security program afterwards. If it doesn’t help, continue with Fix 5 and Fix 6.

If nothing works

• Use System Restore to go back to a restore point from before the problem started (run rstrui).
• Create a new local user account and test whether it signs in and out normally. If it does, the original user profile is likely damaged.
• As a last resort, do a repair install or reset of Windows. See how to reinstall Windows 10; the same approach works for Windows 11.

If the PC gets past the message but shows only a black screen, see Windows black screen: how to fix it.

Related guides

• The Diagnostics Policy Service is not running: how to fix it
• Getting Windows ready, don’t turn off your computer: how to fix it
• Windows Resource Protection could not perform the requested operation
• Windows black screen: how to fix it
• How to reinstall Windows 10

Official sources: for more detail, see Microsoft’s own documentation:

• Microsoft Learn: SENS notifications (event types and the logon notification timeout)
• Microsoft Learn: logoff command reference
• Microsoft Support: How to perform a clean boot in Windows

Frequently asked questions

Is it safe to turn off the PC while it says this?

After waiting several minutes, a forced restart is usually fine, but anything you hadn’t saved is lost. If the screen says Windows is installing updates instead, wait longer, because interrupting an update is riskier.

Should I disable the System Event Notification Service?

No. Windows and many apps rely on it for sign-in, network and power notifications, and disabling it can cause new problems. Keep it on Automatic and fix the program that hangs instead.

Why does it happen mostly over Remote Desktop?

Signing out of a Remote Desktop session starts sign-out work for every component in that session, such as printer redirection, user profile handling and security agents. A server with many users and many add-ons has more chances for one of them to hang.

How long should I wait before restarting?

Five to ten minutes is reasonable. If it happens at every sign-in or sign-out, restarting only treats the symptom; use Fix 5 to find the program causing it.