Note To see usage information for this tool, type PatchRegCleanup /? at the command prompt.
The Patch Registration Cleanup Tool helps resolve some issues that are related to invalid or corrupted update registration. This tool lets you bring the product back to a known state so that you can reinstall updates.
- Under the AllPatches multi-string value. The SQUID for each update, regardless of whether the update is registered, applied, superseded, or obsoleted, is listed here.
- A subkey under the Patches node that is named by using the SQUID of the particular update. This subkey provides more details about an update.
Valid update registration requires that all updates that have their SQUIDs listed under the Patches node and that are either registered or applied updates should also be included under the AllPatches multi-string value. Also, the AllPatches multi-string value should not contain SQUIDs for updates that do not have corresponding registry keys under the Patches node.
When the update registration information is not as expected, Windows Installer cannot perform any maintenance mode operations on the product.
The Patch Registration Cleanup tool addresses some of these issues by removing any registry keys under the Patches node that do not have corresponding entries under the AllPatches multi-string value.
For more information about update registration problems, click the following article number to view the article in the Microsoft Knowledge Base: