Sage CRM 2022 R1 is the first version of Sage CRM to be supported on Windows 11. 

No other versions of Sage CRM currently supported (2019 R1, 2019 R2, 2020 R1, 2020 R2, 2021 R1, 2021 R2) have been tested on Windows 11. 

Customers using supported versions of Sage CRM prior to 2022 R1 are supported on Windows 10.  It is important to note that Windows 10 is not an insecure or obsolete Operating System.  Microsoft is not ending support for Windows 10 until October 14th, 2025, and until that date, Microsoft will continue to provide patches and security updates as needed.  Windows 10 Home and Pro - Microsoft Lifecycle | Microsoft Docs 

Microsoft is ending support for Internet Explorer 11 on Windows 10 on June 15, 2022.  This doesn't mean the software will stop working but it does mean that Microsoft will stop testing Internet Explorer as a browser when connecting to its own services. 

We explained in an advisory in May 2021 that Sage CRM 2021 R2 would be the last version to have its User Interface tested using Microsoft Internet Explorer 11. 

We issued a further Advisory in December 2021 that customers who rely on the Classic or Lite Outlook plugins are advised not to upgrade to Windows 11 

This is because Microsoft Internet Explorer 11 is not supported on Microsoft Windows 11.  Features of the Sage CRM Outlook plugins use ActiveX technology that does not work within Windows 11. 

We are currently redesigning our Email Management features for Sage CRM 2022 R2.  This is due to be released at the end of July 2022.  This redesign will remove all dependency on plugins and aims to be functionally equivalent to the core features of the existing Outlook integration. 

Why is Internet Explorer important for the Outlook Plugins? 

Internet Explorer 11 is tightly integrated with Windows 10.  This includes technology such as ActiveX.  The current integration between Outlook and Sage CRM is provided by plugins (Classic and Lite Outlook Plugins) that use ActiveX to enable the sending of data and the control of CRM screens from within Outlook.   
Microsoft had dropped the use of ActiveX in Edge.  Even when a user was working with Chrome or Edge as their browser for the main Sage CRM interface the Outlook Plugins would still make calls to Internet Explorer because this was the way in which we could use ActiveX within Windows 10.  A user would not be aware of the use of Internet Explorer because the browser was deeply integrated into Windows 10. 

Windows 11 does not support Internet Explorer and does not use ActiveX technologies. 

We have an implementation of Sage CRM 2021 R1 with clients using Windows 10 and the Outlook plugin.  Should we upgrade? 

You should upgrade to Sage CRM 2022 R1 to take advantage of the new features but if you use the Outlook Plugins then you should not upgrade you client machines to use Windows 11. 

We have an implementation of Sage CRM 2020 R2 with clients using Windows 10.  We use CRM Together's Accelerator toolbar in Outlook.  Should we upgrade?  

You should upgrade to Sage CRM 2022 R1 to take advantage of the new features.  Your client machines can use Windows 11 as the Accelerator plugin uses different technology for the integration between Outlook and Sage CRM. 

We use Sage CRM 2021 R1, and we make use of a mix of client machines, some on Windows 10 and some on Windows 11.  Can we upgrade to Sage CRM 2022 R1? 

Sage CRM 2021 R1 was never tested with Windows 11.  When you upgrade to Sage CRM 2022 R1 the supported client environments are both Windows 10 and Windows 11.  Please note the known issue about the support for the Outlook Plugins.