Outbacksam34

So I'm a big Spiderweb games fan and I bought all the Avernum and Geneforge series on disks a while back (around the time that Avernum 4 came out). At the time I was running OS 10.4 and when I went to install Avernum 1 I got an error message that said "You can't open the Application 'Avernum 1.0.2 Full Installer' because the Classic environment is no longer supported". (I got the same error when I tried to Install Avernum 2 and Geneforge 1) Now, I never got around to addressing the problem back then for various reasons. I just contented myself with playing Geneforge 2-4 and Avernum 3-4. But now I've just recently upgraded to OS 10.5 and I decided to go back and try again to see if the problem fixed itself somewhere along the way. Of course, the error is still there and this time I want to do something about it. Can anyone help me out? I think it's the installer that is the problem, not the games themselves, because I can download and play the demos just fine. If I had registration codes instead of disks I probably wouldn't have any problems at all.