microsoft security client error 0x80073b01 Windows

In March after a Windows update, Microsoft Security Essentials stopped working.  I checked the log and it doesn't seem to be able to update the definitions.  I've also tried to log in as Administrator and troubleshoot the problem without any success.  As this was my security package, I need to get it back up and running.  Any ideas on how to fix this problem?



Ans:

Uninstall MSE and reinstall. That worked for me.

Restore points going back do not help.