Windows have function " administrator of tasks " allowing to put an end to programs in motion any time. Sometimes, in the office, in school or in some " cyber coffee " they have their own administrators of tasks to avoid wrong manipulations.
When you meet this type of problems, use AutoSysBot Process Terminator. It is a program allowing to put an end to all processes in motion on your system. Not only it will stop the process of ongoing program, but he will also stop program.