If you have McAfee Antivirus installed on your computer, you may have problem to connect to the camera due to Access Protection built in McAfee Software. To get connection, disable Access Protection in the following way:
1.Right click on the McAfee icon in the right corner go to VirusScan Console.
2.In the VirusScan Console right click Access Protection and click disable.
3. Now, reconnect to the camera.
This behavior can occur with other Antivirus software as well.