The version 9, even if it opens in Windows 7, is not developed for this OS. This might be the reason why when you try to run several commands, you get an error message. In this matter, I strongly suggest that you update your program's version to a newer one. Visit the official website for additional information and download links. If you don't want to use payroll features of the application, you can find another program that has functionality only for invoices in the Software Informer's database.