In that case, if you need to cancel the last actionmade in text, graphical editor, web browser, the application to 3D simulation or any other program designed to enter and/or edit the data, locate the top menu bar item "edit" and select the context menu command "Cancel". The same applies to commands executed in the window of an open folder.
Examine the program interface, perhaps on the toolbar, there are buttons to undo and redo the last command. They usually appear as rounded arrows up and down or right and left. Move the cursor to this button and hold it for a few seconds – a tooltip will help you understand whether you have chosen button. Very often the latter can cancel the keyboard shortcuts Ctrl and Z or Ctrl, Alt, and Z.
If you delete a file, you can try to undo the deletion, as described in the first step, or to restore it from the recycle bin on the desktop. Open the recycle Bin, locate the deleted file and click right mouse button. In the context menu select "Restore". When the computer was deleted by some program, it will need to be reset.
If you worked with system components or corrected settings in any app and managed to apply the new settings or cancel them would be impossible. You must return the parameters that were set before the time of the change or to set the default values by pressing the corresponding button. In that case, if you have not yet clicked OK or Apply, simply click on the "Cancel"button.
In those applications where it is expected to command for a certain period of time (installing new programs, disk defragmentation, scanning your system for virus infected files), you need to interrupt the process and close the window. This can be done by clicking on the button "Stop", "Stop", "Cancel". If prompted, confirm your action.