How do I purchase extended support for Windows 7 Professional?

 It is for their Volume Licensing clients

https://www.microsoft.com/en-us/microsoft-365/blog/2018/09/06/helping-customers-shift-to-a-modern-desktop/

Windows 7 Extended Security Updates
As previously announced, Windows 7 extended support is ending January 14, 2020. While many of you are already well on your way in deploying Windows 10, we understand that everyone is at a different point in the upgrade process.

With that in mind, today we are announcing that we will offer paid Windows 7 Extended Security Updates (ESU) through January 2023. The Windows 7 ESU will be sold on a per-device basis and the price will increase each year. Windows 7 ESUs will be available to all Windows 7 Professional and Windows 7 Enterprise customers in Volume Licensing, with a discount to customers with Windows software assurance, Windows 10 Enterprise or Windows 10 Education subscriptions. In addition, Office 365 ProPlus will be supported on devices with active Windows 7 Extended Security Updates (ESU) through January 2023. This means that customers who purchase the Windows 7 ESU will be able to continue to run Office 365 ProPlus.

Please reach out to your partner or Microsoft account team for further details.

https://www.zdnet.com/article/microsoft-to-offer-paid-windows-7-extended-security-updates/

This time around, the ESU program is being run out of Microsoft's Volume Licensing Unit and Core Windows Engineering "is producing these updates like a product," Spataro explained.

It's your choice what OS you decide to install.

Good luck with it.

FYI:

With end of support Microsoft is not telling you that your operating systems won't work.

What they are saying is that after a certain date they will no longer support them.

Whether they still work or not with particular programs is up to the particular program manufacturers.

Example: Google Chrome is no longer supported for security updates in XP or Vista by Google and Mozilla Firefox is following the same path.

What this basically means with Microsoft no longer supporting an operating system is that even though hackers may find "holes" and vulnerabilities to be able to access the operating systems and cause security problems, Microsoft will no longer be monitoring or rectifying those problems by way of Security Updates each month.

You are on your own in regards to maintaining the Security of your operating systems.

What does it mean if Windows isn't supported?

____________________________________________________

This will show you when support (Mainstream and Extended Support) for the various operating systems ends.

Windows lifecycle fact sheet - Windows Help - Microsoft Support

And these FAQs show you how Microsoft arrived at the Support Lifecycle Policy:

Microsoft Lifecycle Policy FAQ

https://support.microsoft.com/en-au/help/17140/lifecycle-faq-general-policy-questions

@@@@@@@@@@@@@@@@@@@@@@@