My question - if I buy later key to cheaper version of win, could I use this key with my installed win without reinstalling win?
The Windows 8 Enterprise Evaluation cannot be upgraded.
Following the 90 day evaluation period, you will need to replace the operating system on your test computer and reinstall all your programs and data. It is not possible to upgrade the evaluation to a licensed working version of Windows 8 Enterprise. A clean
installation is required.
The terms are straight forward, you have 90 days to try out the product and your applications, afterwards, you must purchase a license as the trial is not extendable. Microsoft states:
Things to Know Before You Start
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.
Activation and Usage Guidelines
Back up your files and settings before installing this evaluation and again prior to the 90-day expiration.
Upon installation, you will have 10 days to activate this evaluation online. Windows will prompt you to activate. A product key is not required for this software.
You must complete activation before August 15, 2013, to use this evaluation.
Once you activate, you have up to 90 days to use the software. You can track the amount of time you have left by referring to the "watermark" in the lower right corner of the Windows desktop.
If you fail to activate this evaluation within the 10-day grace period, or if your evaluation period expires, the desktop background will turn black, you will see a persistent desktop notification indicating that the system is not genuine, and the PC will
shut down every hour losing unsaved work.
Following the evaluation period, you will need to replace the operating system on your test computer and reinstall all your programs and data. It is not possible to upgrade the evaluation to a licensed working version of Windows 8. A clean installation
Best, Andre Windows Insider MVP MVP-Windows and Devices for IT twitter/adacosta groovypost.com
Did this solve your problem?
Sorry this didn't help.
Great! Thanks for marking this as the answer.
How satisfied are you with this reply?
Thanks for your feedback, it helps us improve the site.