Consider the following scenario. You install a Windows Internet Explorer 7 update from Windows Update or from Microsoft Update. Then, you start Windows Internet Explorer 7, and you try to visit an external Web site. In this scenario, you may receive the following error message:
Webpage cannot be displayed
This problem may occur because the file signatures for the core Windows Internet Explorer 7 files may be changed when the update is installed. If a third-party security program is installed on the computer, the security suite programs may not have the correct updates to recognize the updated IE files and may block Internet Explorer from accessing the Internet.
To resolve this problem, contact the vendor of the third-party security program for an update. If an update is not available, try reinstalling the third-party security program. After you reinstall that security program, the updated Windows Internet Explorer 7 files may now be able to access the Internet.
For information about how to contact the vendor of the third-party security program, click the appropriate article number in the following list to view the article in the Microsoft Knowledge Base:
Hardware and software vendor contact information, A-K60781
Hardware and software vendor contact information, L-P60782
Hardware and software vendor contact information, Q-Z
Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.