I recommend using DOSBox. This program allows you to run DOS programs on a variety of platforms including Windows and Mac OS X. The links below will take you to the DOSBox tutorial page on Wikipedia and the DOSBox home page where you will find full instructions on how to use and download the latest version of DOSBox on your computer.
DOSBox tutorial 
www.dosbox.com

Users with older versions of Windows (e.g 32-bit Windows 7, Vista, Windows XP and earlier) will be able to run in DOS mode by typing 'COMMAND' directly into the search box at the bottom of the START menu or after selecting 'RUN' in the START menu. There may be problems using this method when running a program in full screen mode (ALT-ENTER) as the program may overlap or not completely fill the monitor screen. Rather than changing your display settings, it may be easier to use DOSBox and configure it specifically to your monitor using the Manual and Options files provided - DOSBox 0.74-3 Manual.txt and DOSBox 0.74-3 Options.bat.

I would recommend setting up a new folder (e.g. DOSPROGS) in the root directory of your C: drive and then sub-folders within that for your DOS program files (e.g. C:\DOSPROGS\DOS_FRED). You can then move the downloaded files (or extract the zip file) to that folder. Be careful to limit folder and file names to 8 characters as in the original specification of DOS.