They are just that, they are usually found from the result of a recaptured MSI. As everyone else will say on these forums over and over again, it's not a good idea to repackage an MSI. If you thought that you wasn't then just check the setup.exe file cannot be extracted using winzip or some other archive software to give an MSI. Check also that the installation does not drop out an MSI to the temp directory that you can use instead.
