Here's Windows 8.1 Pro Retail With GA Rollup 1 for both 32 and 64 bit versions. Further info included.
Windows 8.1 Pro offers enhanced features to help you easily connect to company networks, access one PC from another, encrypt your data, and more. Important: Windows 8.1 Pro full version is for Windows 7 users only. Currently running Windows Vista or XP? First upgrade to Windows 8 Pro.
Please note that:
Make sure you’re on the PC you want to upgrade. If you're updating to Windows 8.1, this PC must be running Windows 7 or Windows 8.1 Preview. If you already have the latest version of Windows 8 installed on your PC, you can update to Windows 8.1 in the Windows Store for free.
If you're upgrading to Windows 8, this PC must be running Windows 7, Windows Vista, Windows XP with Service Pack 3 (SP3), Windows 8 Release Preview, Windows 8 Consumer Preview, or Windows Developer Preview.
Windows Setup checks that your PC meets all system requirements before it installs Windows 8.1 or Windows 8.
Special thanks to november_ra1n for providing the original ISO images with all detailed activation requirements! All the keys provided here in this package have been tested on December 12th, and all went smooth for activation.