How do I change the installation directory?

I'm trying to install a disc that I found that is labled: Xplosiv RollerCoaster Tycoon 3 and RCT3 Soaked. I went to install it and it has no option to change the install directory.How do I change the installation directory?RTC3 asks about the installation type during the installation process there is a custom installation choice check that so the drive change option will be enabled.