Log in issues with Laptop

Hello! Sometimes when I log in from my laptop, it takes more time than the usual amount of time it takes to log in. After it logs in, the background is changed to black, the interface seems like the one from an old window like windows 98 and a message pops up on the bottom right corner of my screen. Following is the message "Failed to connect to a windows service. Windows could not connect to the System Event Notification Service service. This problem prevents standard users from logging on to the system. As an administrative user, you can review the System Event Log for details about why the service didn't respond" I am a windows 7 user, any reasons why this happens with my laptop? Thanks in advance for help!
