This program will simply patch the GetDriveTypeA/W function in any other program, a function that is commonly used to check whether a given parameter (drive) is a CD / USB / HDD etc.
This program is mostly used to play games without cd, something like a universal NOCD. Please note that some protections involve filecheck after the drive is checked, for instance the game Grand Theft Auto: Vice City. I copied the whole content from the CD to my hdd, used CDDisabler and voila, no cd required! Get CDDisabler and take it for a spin to see what it can actually do for you!