Originally Posted by hakans
But isn't it possible to uninstall ISPConfig 2 first and then install ISPConfig 3? The server is able to run without ISPConfig so to uninstall it would not be a problem. Right?
No, this wont work as ispconfig 3 requires different software and a different configuration then ispconfig 2.
If you want to switch to ispconfig 3, make a backup of you sites and databases, format the server and reinstall it as described in the ispconfig 3 instructions.