Press Ctrl + Shift + Esc to open Task Manager
Find Microsoft Excel in the Processes list
Select Excel
Click End task
If Task Manager does not open, press Ctrl + Alt + Delete and choose Task Manager
If Excel is frozen but Task Manager works, end any related Excel processes
If needed, right-click the taskbar and open Task Manager from there
If Excel still will not close, restart Windows
If the system is unresponsive, press and hold the power button to force shutdown