Where is user customized database directory saved?

Assume I setup an older eMClient in the past and adjusted in

Settings–>Storage—>User database storage

to folder

D:\email\emclient\mystorage\

Now I, backuped this folder, then uninstalled eMClient completely and re-installed the newest version (on 64bit Win 7).

Much to my surprise the new installation found automatically (!) my previous user database storage directory.

Why this?

If I uninstall everything then there should be no tracks left where a new eMClient installation could find this information. Even not in Registry.

Nevertheless eMClient found it!

Where exactly is this directory path stored?

Peter