ervis,
I suspect that the issue may be that OEM keys, such as the one on your computer, only work with the correct version and language of Windows installation. I am completely confident that your OEM key will work with a Windows 7 SP1 image but it needs to be the correct version and language. I have done dozens of installations using Windows 7 SP1 ISOs and activating the install with the original key from the COA.
The problem appears that there isn't an Italian Home Premium version listed. I have updated my original post to include links to another list of ISOs, another Windows 7 guide, and a "ei.cfg Removal Utility". Most Windows 7 ISOs contain most versions (Basic, Home Premium, Professional, and Ultimate) of Windows 7. The "ei" bit determines which version of Windows is installed by the disc. This tool removes the "ei" bit from the ISO and allows the ISO to act like a universal installer.
For example, if you download Windows Professional 64-bit Italian (X17-24297 or X17-59215, provided your COA doesn't list E,N, or K on it) and you run the "ei.cfg" toll on the ISO, the ei.cfg bit will be masked and the "new" ISO will allow installation of Windows 7 Basic, Home Premium, Professional, or Ultimate. Just remember that you still need a vaild key for the version you install.
As far as the X16-96072 ISO is concerned, I can't help you and I don't think anyone else can either. To the best of my knowledge, all of the original Windows 7 non-SP1 ISOs have been removed and replace by the SP1 ISOs. At this point, all I can say is download a version of Win 7 Pro Italian 64-bit, use the "ei.cfg tool" on it, and burn that. Now install Windows, selecting Home Premium and hope for the best. Only enter the key after Windows is complete installed... you may need to call the Microsoft for phone activation.
Please send KUDOs