When you come across the warning message like this,
you can get rid of this after taking the following procedures.
1. In case of Windows XP, go to the step 2.
In start menu, program > Internet Explorer, right click and run as an administrator.
Then go to the same page you see the warning message.
2. Click [go further on this site (not recommended)].
Then click the [error of the certification], and click showing the certification.
3. See the certifier, and click [install]
4. [Next]
5. Select [deploy all certifications on this store]
6. Select [trusted root certification authority]
7. [Yes] in the next screen
