The version that Digit has given on its DVD in May 2005 is only Linspire Live! Of course, it can be intalled on the hard disk, but it will still remain a limited version.
As for the options that vrnoormd gave, I didn't see them. I could see only 2 options. One of them was proceed with the boot. Choose the other option and you will see be able to find out the installation.
But I will still recommend that you don't install that on your hard disk. Opt for some other full version instead of a live one.