Hello,
First of all, we would ask you to download the latest version of Hello Engines! from our website here:
http://www.hello-engines.com/download.htmThis is version 6.5.8 and with your unlock code from 1&1 you should be able to unlock this one as well.
The other problem could be a DEP (Data Execution Prevention) problem, please try the following:
1.) Click Start -> Settings -> Control Panel and select System.
2.) On the Advanced tab, under Performance, click Settings.
3.) On the Data Execution Prevention tab, add Hello Engines! to the list of exceptions
Does this help?
Best regards