Microsoft has published the final RTM version of Windows 8 to MSDN and TechNet Subscriber Downloads portal for developers and IT professionals to start working on and preparing for the general availability of Windows 8 on October 26th, 2012.

If you’re not a MSDN or Technet subscribers, Microsoft is also releasing a version of Windows 8 for free download which is predefined with a free MAK (Multiple Activation Key) product key that can activate the system for 90 days validity.

The Windows 8 available free download is Windows 8 Enterprise edition with 90 days evaluation period, primarily meant for developer and IT professionals to build and test Windows 8 apps on the final version of Windows 8.

Windows 8

Both 32-bit and 64-bit versions of Windows 8 Enterprise ISO images are available in the following languages: Chinese (Simplified), Chinese (Traditional), English, English (UK), French, German, Italian, Japanese, Korean, Portuguese (Brazil), and Spanish.

A few things to note for Windows 8 Enterprise Evaluation edition:

  • The evaluation edition will expire and cannot be upgraded.
  • To upgrade, the evaluation must be uninstalled and a non-evaluation version of Windows must be re-installed from your original installation media.
  • Consider running the evaluation edition in a virtual environment or installing on a separate hard drive or partition. The will allow you to upgrade your original Windows installation to Windows 8.
  • During registration (required) you must login with a Microsoft account and provide your name, e-mail address and country.
  • You are required to activate the product online within 10 days after installing.
  • Once the evaluation is installed, you cannot upgrade. To revert to a previous version of Windows, you must do a clean install from your original installation media.

Windows 8 Enterprise Evaluation ISO can be downloaded from

In most cases, Windows 8 Enterprise will automatically activate itself after installation for 90 days free evaluation period. But if activation is not been done within the 10-day grace period, or if the evaluation period expires, the desktop background will turn black, a persistent desktop notification indicating that the system is not genuine will be displayed, and the PC will shut down every hour, losing unsaved work.

In addition, Windows 8 Enterprise also comes with one rearm count. It means that user can perform a rearm and reset of activation status once on the installed system. If the rearm command is performed at the end of first 90 days evaluation period, then the second 90 days activation period can be activated, giving a total of 180 days continuous usage of Windows 8.