In the distributions mentioned above libstdc++.so.5 is not an independent rpm anymore but is a part of compat-libstdc++.rpm. Depending upon distribution and architecture the complete file name is
or similar. Installing the appropriate RPM for the architecture will allow the GroupWise Installer to run.
In some instances, the 64-bit version of the libstdc++.so.5 libraries are installed on the SLES 10 server, but because GroupWise is a 32-bit application, you need to install the 32-bit version of that library. To do that, open YaST and go to Software Management, then use the Search function to search for "libstdc++" and check the box for libstdc++33-32bit and click "Accept", which should install the necessary library. After that installation completes, the GroupWise installer should run successfully.