Copying Deus Ex, Project IGI or Oni

[PhysEd]

Hi, I am looking to create backups of these games and wondered if anyone has any info about how to copy any of them. I especially would like to copy Deus Ex, as my brother is borrowing it and I have uninstalled it whilst playing Project IGI and Oni. So I would like to create a copy to use while he has it. But I would also like to create backups of Oni and P:IGI too.

Any help would be greatly appreciated

Thanks.