Dear Per-Arne,

please open a new post with your licence key and give me more info regarding the issue: do you receive an error message? Do you have the 3.5 framework on your pc?
Please answer these questions in a new post.
Thank you!

No error message.

I cannot start the program. I am going to check my framework 3.5.

Is framework a Microsoft software?

Thank you for getting back to me!
Please try the following procedure that will delete your frameworks completely from your computer:

1. After you have removed every version of .NET you need to use the .NET FX Cleanup:http://cid-27e6a35d1a492af7.skydrive.live.com/self.aspx/Blog_Tools/dotnetfx_cleanup_tool.ziptool
2. Then please install the .NET 3.5 framework from the following link:http://www.microsoft.com/downloads/it-it/details.aspx?FamilyID=d0e5dea7-ac26-4ad7-b68c-fe5076bba986&DisplayLang=it

After, please read carefully this post and make sure you install the correct framework http://answers.websitex5.com/post/23939 then, please check that your system requirements are compatible http://answers.websitex5.com/post/23835
What version of IE do you have on your computer?
Please keep me informed!
Thank you!