how to make complete clean installation?

Since the last update I Cant get emclient working anymore, even with an old version.
I have tried to uninstall en make a new install, but somehowe old data is left on the computer which keeps me from a total clean installation, how can i solve this issue?

up!

Try deleting c:\users[user_name]\AppData\Roaming\eM Client.  Then reinstall.  This is a hidden directory, so make sure they are displaying.