The easy fix is described in this Microsoft Knowledge Base Article:
Windows Installer CleanUp Utility
If that doesn't help, you'll need to delete an entry in the registry under the following key:
HKLM\Software\Classes\Installer\Products\<Application ID>
The <Application ID> is different for each installation, so must be determined from the error log. That can be done as follows:
- Log in as Administrator.
- In Control Panel, double click Administrative Tools and then Event Viewer.
- In the tree view, select Application then look in the Source column of the list view for the most recent "MsiInstaller" entry, with a corresponding error in the Type column.
- Double click on that entry, and it should say that it failed to read the PackageCode, and give the location of the registry key causing the problem.
- Click Start/Run and type regedit.
- Browse to the given registry key and delete it.
- Close regedit and Event Viewer.
- Reinstall TextPad.
Keith MacDonald
Helios Software Solutions