I am trying to set up a Windows Server 2008 R2 virtual machine set up with an Italian version of Windows for testing. I can download Italian install media from my MSDN subscription, but I've also seen that I can install an Italian language pack on a standard English Windows system. Is there a difference between these 2 methods? Is the foreign language install a different OS than the standard with language pack?
The actual Windows OS is language-neutral since version 6.0 (Vista/WS2008); the various localized installation media simply have a pre-installed default language pack, to which you can add additional ones later. If you don't install any additional language pack, you can only use the language that has been pre-installed.
Installing from an English media and adding the Italian language pack has the exact same end result as installing from an Italian media and adding the English language pack: you can switch between the two languages using the regional settings in Control Panel.