Windows 8.1 Pro (Professional) edition is developed for professional and small business use. It has more features than Windows 8.1 Core original release. The most remarkable features of Pro edition are BitLocker, Group Policy Editor and Encryption.
Windows 8.1 Pro 64-bit version supports up to 512 GB of RAM. It has more flexible options which are suitable for business and professionals.
If you have been using any edition of Windows 7 (except Windows 7 Starter Edition), you can upgrade from Windows 7 to Windows 8.1 Pro.
Windows 8.1 Features
Boot direct to desktop
In Windows 8, the start screen used as first screen after user login. The users had to click desktop tile from start screen. That was kind of painful extra step. It got fixed in 8.1 where traditional desktop is the first screen after login.
Set default apps
Do you like to keep old Internet Explorer browser as your default Internet browser? Nobody likes it (even Microsoft employees, unless forced, probably). Windows 8.1 allows switching default browser and other apps like photo viewer, media player etc.
No, it is not that you are thinking. It is the same Windows 8 start button but with some improvements like right click options and a few more enhancements. Yet it does not bring start menu like Windows 7 or Windows 10 etc.
If you ask us, start button and start menu contributed above 70% towards Windows 8/8.1 failure. Microsoft stuck with it unless total destruction of Windows 8 usage.
Tiles could be resized to small, medium. large and wide sizes. Though not amazing, it was useful feature to organize start screen.
Auto app update
Windows metro apps can be set up to update automatically to newer version. You can enable/disable Automatically update apps option.
Download Windows 8.1 Pro ISO
Choose 64-bit (x64) or 32-bit (x86) ISO file.