I today attempted to install Zune PC Client on a Windows 7N, x64 system. That’s a no-go!
Basically, the installation complained that it could not find some media SDK file, what ever? It seems that N-version of the Windows family does not come with Media features included, hence you need to download these yourself.
For N-versions (64 bit), you should go here:
After having installed this update, you can go about installing the 64bit version of the Zune Client.
Ultimately, you end up with this: