Consider the following scenario. You install a security package on a Windows Vista-based computer. Then, you restart the computer. In this scenario, the computer restarts repeatedly. Specifically, after you restart the computer, the Windows Vista startup screen appears. However, the computer then restarts instead of finishing the startup process.

This problem occurs if the security package is signed by using the method that is described on the following Microsoft Developer Network Web site:

http://msdn2.microsoft.com/en-us/library/ms925908.aspx

Note: The security package that causes this problem may be offered by a third-party cryptographic service provider. A security package is a software implementation of a security protocol.

When you install an .msu update package on a computer that is running Windows Vista, you may receive the following error message:

The Windows Modules Installer must be updated before you can install this package. Please update the Windows Modules Installer on the computer, then retry Setup.

When you use a script to install the .msu update package, the installation fails. When this problem occurs, the Wusa.exe process returns error code 0×800f0823.

When you try to extract and to view the contents of a Microsoft Update Standalone Package (MSU) for Windows Vista, you cannot extract the files from the MSU.

For example, one of the following issues may occur:

• If you try to use the /x command-line switch at a command prompt to extract the file on a Windows Vista-based computer, a dialog box that contains command-line help for the MSU opens.
• If you try to open the file on a computer that is not running Windows Vista, you cannot open the file. Instead, Windows prompts you to locate the program that created the file.