|Did you download an iso or exe ?|
I will assume you downloaded a disk image or the file says at the end .iso versus .exe
You can use just about any free program to mount an image .... you want a virtual cd/dvd drive software. Follow the instructions for the software download and configuration. Mount the drive - give it a drive letter and assign it the 2003 file. :)
this is an example ... http://www.slysoft.com/en/virtual-c...
I'm still learning everyday.