Another way: if the computer is still sending data to the printer, on a classic Windows desktop, the printer icon in the tray (bottom right) will be visible (or it might be in the hidden group, click the little up arrow to display).
Right click on the printer icon, then click on the printer. The current jobs will be displayed.
RC on the job to be cancelled and click on Cancel.
If there's no Windows printer icon, all the remaining data will be in the printer memory.