I noticed that after installing cdt, Eclipse always loads the default workspace. The workspace listed in the config.ini
in osgi.instance.area.default
Sometimes you need to pay attention to howw Eclipse is launched. I ever pinned Eclipse by rigk-click on the excutable and pinning it to taskbar. In this way, the Eclipse is launched to use settings under c:\User\public\public Documents\eclipse" which is not very desirable.
However, if you pin it by creating a short-cut, then it will launch to use settings in the folder of Eclipse installation. Then everything makes much more sense.