Article ID: 814833 - View products that this article applies to.
When you try to restore your computer running Windows XP to a restoration point before you applied a patch or service pack, the application that you applied the patch to may reach an unusable state. When you try to repair, install, reinstall, or remove the application, you may receive the following error message:
"This patch package could not be opened. Verify that the patch package exists and that you can access it, or contact the application vendor to verify that this is a valid Windows Installer patch package."
This problem occurs because Windows XP System Restore does not monitor the Windows Installer Patch (.msp) files. When you install the patch files, the cached patch is not restored in the Windows Folder\Installer folder. Also, Service Pack 2 (SP2) is cumulative. It contains the previous Quick Fix Engineering (QFE) files. After you install SP2, the individual QFEs that you installed become obsolete. Windows Installer removes the configuration data for the QFE patches including the registry keys.
Because the cached patch is missing when you use System Restore, Windows Installer tries to cache the patch again from the patch's registered source location. However, the registered source location for many application patches is the Temp folder. This folder is a transient source location. Typically, the files in the Temp folder are deleted after you use them. Therefore, the files that Windows Installer tries to locate in the transient source location may not be found. The error occurs because Windows Installer cannot locate the Windows Installer Patch (.msp) files.
To work around this problem, reapply the patches that are missing. If the patch location is a network or media share that is available, you may be able to locate and to apply the patch from there. You can also install the latest Service Pack patch for the application because the latest service pack contains the previous QFEs. The cumulative patch applies the missing patches to the application and makes the individual missing patches obsolete.
Steps to Reproduce the Behavior
For additional information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/302796/EN-US/ )Troubleshooting System Restore in Windows XP
(http://support.microsoft.com/kb/303354/EN-US/ )Error Message: System Restore Was Unable to Create a Restore Point
(http://support.microsoft.com/kb/310405/EN-US/ )How to Turn On and Turn Off System Restore in Windows XP
(http://support.microsoft.com/kb/306084/EN-US/ )HOW TO: Restore the Operating System to a Previous State in Windows XP