After installing a customized Windows 7 Home Premium x64 I can't install msi files. I get the following message: "This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows Installer package".

 

I defined the ProgramData e Users folders in drive E

 

Thank you

to less info for a qualified help!

I hope it isn't too late but here are a few options/solutions:

1) run software in compatibility mode (try Win XP SP3) and/or as administrator

2) create new user and log in through it

3) log in as administrator: open Command Prompt as admin (right click -> "Run as Administrator"), type net user administrator /active:yes log out and log in as administrator

Good luck with it.