The System Event Notification Service service terminated with the following error: Overlapped I/O operation is in progress

Question

When I start my Windows 7, I get a notification

The system event notification service could not be started....

As a result, I dont have Aero, even though my Windows Experience Index is 3.2.
Aero used to work fine before today and I have not installed any new application. I have checked the event log and it reads:

The System Event Notification Service service terminated with the following error:
Overlapped I/O operation is in progress.

I am not sure what this means.

I have seen the services.msc and everything is fine there. Moreover the startup time has also extended and the Please wait stays for more than a minute. This is a sudden problem as everything used to work fine until today.

For Aero I have tried starting Desktop Window manager (as pointed out by the trouble shooter), but with avail. From what I could understand from the forums, the lack of Aero and increased start-up time comes from a single problem of the System Event Notification Service.

This is a personal Computer and I have no active directories installed.

Answer 1

Check your system for malware first

What to do if my computer is infected by a virus or a malware?

Then if the system is clean, try a Windows restore point, choose a restore point before the strange behavior started. System restore may not solve the issue if the system is infected by malware.

http://www.howtogeek.com/howto/11238/using-system-restore-to-recover-your-windows-7-computer/

Answer 2

I have this problem on my machine. It's been this way for a very long time. A temporary solution is to open services.msc, scroll down to the System Event Notification Service, and restart it. Then restart the computer; this usually fixes the problem for a little while. I'm still looking for a better solution.

If anyone has a fix for this problem, I'd love to know about it. My system is clear of malware, and a system restore is not an options since this problem has been in place for so long.