System drive compression causes a driver installation to fail if the driver does not have a digital signature in Windows Server 2003, in Windows XP, and in Windows 2000

You compress the system drive on your computer that is running Microsoft Windows Server 2003, Microsoft Windows XP, or Microsoft Windows 2000. If you then update a driver by installing a file that does not have a digital signature, the installation appears to be successful, but the driver is not updated. Alternatively, if you update a driver by installing a file that does not have a digital signature and then compress your system drive, the driver reverts to its earlier version.

This issue occurs because the original driver is protected by Windows File Protection (WFP). When you write to a file that is compressed, WFP replaces the updated file with the previous file that has a digital signature.

To resolve this problem, use one of the following methods:

• When you compress your system drive, do not compress the root directory, and do not compress the Windows directory. In Windows Server 2003 and in Windows XP, the Windows directory is named "Windows." In Windows 2000, the Windows directory is named "Winnt."
• If the original driver is protected by WFP, do not use a file that has no digital signature to update the driver. To obtain a driver update that has a digital signature, contact the company that released the driver.

This behavior is by design.