Dear customer,
We tested the old version 5 on windows 7 machine and I could install it with no problem. Would you please give us more details about this error? What is the detailed error message on your screen?
Two possible reasons:
1. Version 5 is designed for Windows 7, Vista, XP and other Windows systems that support .net framework 1.1. If you are using Windows 10, 8.1 and 8, we suggest you to install the latest ezCheckPrinting version 6.
2. Version 5 security digital signature has expired. Since it is an old version, we did not renew the digital signature. If your machine has higher security settings, you may see the error "the publisher could not be verified."
Thank you.