Verified answer

Go to the task manager(alt+ctrl+del and select task manager from the screen) choose the program and click on end process if this doesnt work click on the "process" tab on top of the task manager and find the program and click on end process from there............but be careful to not to close any other file as it may make your pc crash...............if all of this doesnt work re-install windows. plz dont forget to mention specs and the version of windows or the name of the operating system.

Press Alt+Ctrl+Delete go on Processes, slelct the program executable name and then End Process

Try Pressing alt + f4