Windows 10 is not quite ready to be installed in brand new PCs. Because of this, new PCs will not see Windows 10 pre-installed in them until after the official release date of July 29, CNET reports.

Microsoft is not ready to release a final version of Windows 10 to vendors. That means that PC vendors will have to wait until they are finished making the final adjustments to the upcoming operating system.

PC vendors would have to test out Windows 10 on their brand new machines before selling them to the public and there just is not enough time for that. Bloomberg reports that new computers seen in stores on July 29 likely will not have Windows 10 pre-installed in them. Bloomberg cited a comment from Yusuf Mehdi, vice president of Windows and device marketing.

"You will see computers running with Windows 10 installed very soon after the 29th and then in the fall a whole new class of machines for the holidays," Mehdi said. 

Microsoft is trying to perfect Windows 10 and they have spent months making improvements to it. Microsoft wants to make a fully functional and user-friendly operating system that is free from bugs and major issues. When Microsoft introduced Windows 8, users complained to the company with many issues, including a missing start button. 

Microsoft would rather deliver a bug-free Windows 10 than rush its release so that everyone gets it on July 29.

In June, Microsoft announced the July 29 release date of the new Windows 10. It was thought that everyone would be able to upgrade to the new Windows on that date. However, it is now known that not everyone will be able to get Windows 10 on the day it is released.

The most loyal Windows users, those who chose to take part in the Windows Insider Program, will be able to upgrade to Windows 10 first. Others might have to wait a couple of days before they will be able to upgrade.