There is no assigned hotkey or shortcut key for defragmentation in Windows 11/10. However, you can quickly open the Defragment and Optimize Drives window for defragmentation on your Windows PC in multiple ways. For example, you can open the Run Command (Win+R) box, type dfrgui, and hit the Enter key. Or else, you can type defrag in the Search box and use the Enter key for defragmentation.