Every time I install software that uses a Windows Installer package, a pop-up dialog box asks me to locate missing files in the C:\temp\\{8851E12C-0EF9-11D4...\} folder. I can never locate these files. Regardless of the application I'm installing, the initial dialog box asks for the same directory reference mentioned above. How can I eliminate the message?

What you see is an artifact from a previous Windows Installer package that didn't finish properly. To eliminate the message, you need to locate the offending package in the system registry and manually remove the problem value.

You can use regedit.exe's built-in Find feature to find the package. However, for this kind of search, I prefer third-party products such as Steven J. Hoek Software Development's (http://www.iserv.net/~sjhswdev) Registry Search + Replace, which are better for finding matches or partial matches of search strings within registry keys, values, and data. Using the tool of your choice, search the registry for the exact directory name specified in the dialog box that appears, which Figure 1 shows. You'll probably find the directory name in the HKEY_CURRENT_USER\Software\Microsoft\Installer\Products registry subkey. This subkey contains individual Windows Installer packages, each with a unique reference number. Each package's subkey contains a SourceList subkey, which references the source file locations for that package. This subkey might also have subkeys named Media and Net, and the directory reference that your error message references will most likely be the data contained in one of the values under the Net subkey. The safest way to solve the problem is to delete only the value that contains the offending directory reference. I don't recommend deleting anything else unless you are 100 percent certain that the parent Windows Installer package isn't installed on the machine.