I am trying to install Sun Studio 12 on a machine where Sun Studio 11 was present before.
I have uninstalled all "dbx" and "Sun Studio 11" related packages but still, while launching the command "./batch_installer --accept-sla" I get the same result:
You may not install "on top of" an existing release!
Please inform me what needs to be removed in order to install Sun Studio 12.
You don't have to uninstall a previous release to install another. You just can't install them both in the same location. Tell the installer to use another base directory.
If you completely remove Studio 11, you can install Studio 12 in the location where Studio 11 was. How to remove Studio 11 depends on how you installed it. If you used the batch or GUI package installer, use the uninstall script that came with Studio 11.
If you installed from a tarfile, just delete the entire Studio directory tree. (Don't do this if you installed from packages.)
BTW, Studio 12 is rather old, released in 2007. You can get bug fixes and enhancements for it only if you have a service contract. If possible, you should use the current version instead, Studio 12.3.