A suggestion:

Before delivering an application run your install program on a “clean machine”, to be sure it will work at the client site. Never test on a development machine is a rule I believe in. I use a separate computer and reformat the hard disk then load the operating system. When all is working I then load the application to begin testing. . If more than one operating system will be used I test using each one. I would rather find a problem at my test site than at the clients.

Tom