By default, Windows displays Preview Thumbnails when you roll your mouse cursor over an icon in the taskbar. The intent behind this is to give you a visual preview of the available windows currently open in that application. You can click a thumbnail to jump directly to that window, and for most people this behavior is desirable.
But some people prefer a more minimal Windows experience, and choose to turn these previews off. Sadly, there is no UI available to disable these preview thumnails. Furthermore, there isn't even a way to completely disable them under-the-hood. However, we can use a clever registry trick to change the time required for your mouse-hover to trigger the preview thumbnails to display. We can change this to such a high value that you'll never experience a preview thumbnail under normal PC usage.
This utility is a one-click solution to disable or re-enable Taskbar Preview Thumbnails in Windows 10. It will not work for other Windows versions.