Windows 10's new build 10565, just issued to Fast Ring Insiders, has resolved a significant issue for many Microsoft customers . Users can now do a clean install of Windows 10 on their system using their existing Windows 7, 8, and 8.1 product keys without first upgrading their devices.

We just brought you the news of a new Windows 10 update which introduced some great new features like Skype integration, Improved Cortana and Edge browser, and various bug fixes for issues and problems being experienced by users who have already upgraded.

The biggest change however, may come in the form of the improvements in the procedure for those who haven't yet made the leap to Microsoft's latest operating system. Existing product keys for Windows 7, Windows 8 and Windows 8.1 can now be used to activate Windows 10 for PC users that don't count themselves among the over 110 million who have already upgraded.

This is an extremely significant development because up until now, potential upgraders were unable to perform a clean install on their system, and forced to first upgrade their computers from Windows 7 or 8 to Windows 10, automatically registering their device with Microsoft. Then, users had to format and do a complete Windows 10 clean install.

Angry customers plastered Microsoft message boards with their complaints, and apparently the company was listening, as Windows and Devices Group Vice President Gabe Aul announced the improvement on the official Windows blog. "We have received a lot of feedback from Insiders on making it easier to activate Windows 10 on devices that take advantage of the free upgrade offer to genuine Windows by using existing Windows 7, Windows 8 or Windows 8.1 product keys, " wrote Aul.

Referring to the latest Windows 10 Insider Preview, Aul said that users for whom the build doesn't automatically activate upon installation, "can enter the product key from Windows 7, Windows 8 or Windows 8.1 used to activate the prior Windows version on the same device to activate Windows 10 by going to Settings > Update & security > Activation and selecting Change Product Key."

Then he mentioned that users may perform a clean install by booting from media such as a USB stick by entering their previous Windows product key. This is great news for users, but also raises questions, such as whether a product key previously used on another device can activate Windows 10, whether that device would then be deactivated, and if keys may be deregistered and used to upgrade an alternate PC. Microsoft has yet to comment on these issues, but the new rules are definitely a step in the right direction.