Read this thread for downloads: viewtopic.php?f=32&t=28308
Short story: The game installer runs in 16-bit, Microsoft dumped 16-bit application support in 64-bit operating systems. The installed game is 32-bit though, so with some manual patching it can run directly on a host 64-bit system. If that sounds too complicated, then the slightly less complicated option is to install a virtual machine application (VirtualBox, VMware, etc.) and use Windows XP 32-bit as a guest operating system to install the game normally.