HELP Please! Lightroom upgrade impossible!

Hello everyone. Last friday I received my iMac back (new hard disk...according to call back program). From my backup everything is back on my Mac at the moment (inlcuding working LR3.6).

2 weeks ago I bought LR 4 upgrade version (DVD). I did not install it then, because some here said that it would be better to do that, once the hard disk was changed by Apple. Now I'm trying to install upgrade to LR 4 (from DVD). Everything I see during installing (in Dutch); something went wrong , please contact software supplier...(that would be Adobe). There is NO way I can upgrade to LR4!

Can someone PLEASE tell me what to do??? Thnxs very much for any help!