Sybase installation hangs

First remove the local ASE12CLT folder. Then clean the registry either by hand, or you can use the programm Regcleaner 4.3 (http://www.download.com) which can also handle the registry of W2k and Win XP. Just start the programm and follow the leads.
Afterwards reboot, copy the content of the ASE12CLT folder from the CDRom locally to eg c:\temp.
Copy the complete jre-1_1-nt386 folder to the same local folder. Remove the read-only from all files and perform the setup.exe; be sure that the destination of the Sybase install is either D:\ASE12CLT or, if no D drive C:\ASE12CLT.
Reboot machine if requested; start the setup.exe from the CDRom afterwards to install Symposium Client. It will return a few errors, because Sybase is already installed. Just continue the installation. Do not overwrite any *.dll files.
This way you should have a clean install.

If you would like to run the fat client also on a P4 machine, be sure that you download the patch from http://www.sybase.com/content/1013241/sy_jre1.1.zip and extract the content to this C:\Temp folder (overwrite all files if prompted)