NO not cracks. You know how you have to have a disc in to play the game,well the software allows you to emulate the disc by putting the game on a virtual drive. It seems my discs always get scratched up after a period of time and become useless.
Well you can use different programs for this purpose, one is using Daemon-Tools (which is my favourite) to mount images with. But you have to make images of your CD's first, usually .iso files are the best. But do note, that if you have a game like Soldiers: Heroes of World War II, you won't be able to play it by mounting a CD image of the game. Blame the copyprotection . When I tried to do that I had to unplug my CD-drive to be able to do this, but then when I wanted to play some game I still only had on the original CD's I had to turn off the computer again and plug the CD-drive back in.