I usually install and uninstall different versions of Eclipse for fun. I don't want to install many plugins. I prefer to start with fresh install to test the IDE.
The problems comes when I have to config all the external tools that I always use (E.g. run jconsole).
Also I want to backup my launch configurations.
Do you know where Eclipse save this launch configurations?
As I said in this question "Which eclipse files belong under Version Control", the .launch xml files (launcher definition) are found in
[eclipse-workspace]\.metadata\.plugins\org.eclipse.debug.core\.launches
You can actually move them into your project directory:
when your project is refreshed, those configurations will be displayed in the "Run configuration" dialog.
That way, those launch parameter files can be also managed into a VCS within your other project files, instead being buried within the workspace metadata area.
Warning: do uncheck the option "Delete configurations when associated resource is deleted" in the Run/Launching/Launch Configuration preference panel: it is common to soft-delete a project in order to import it back again, to force a reinitialization of the eclipse metadata,... but this option, if checked, will removed your detailed launch parameters!)