Installation ended prematurely because of an error.
Well I am using Shrew VPN Client which is freeware and allows to import the Cisco Client pcf configuration files.
After the import and first try to connect it ended up just with "bringing up tunnel ...".
I had to make one more manual step: Uncheck and Check again the Shrew Soft Lightweight Filter on the connection properties tab. (Configure the connection which connects you to internet).
After that everything worked ok for me.