The 64-bit version supports up to 192 GB of RAM , compared to just 16 GB in Home Premium.
Occasionally, Microsoft maintains links for subscribers of the Visual Studio (MSDN) subscription service. These are the gold standard for safety but require a paid subscription.
An ISO file is a digital archive of the data found on an optical disc. In this context, a Windows 7 Professional ISO is a virtual copy of the installation DVD. It allows you to create a bootable USB drive or DVD to install the operating system on a computer.