@Tobias, Luis
Have you tried restoring the Windows Installer registry settings as well?
How to restore the settings on Win 7 is described in the KB article Christopher Gracia referred to above:
http://support.microsoft.com/kb/2642495.
I also read this KB article about error 1603: http://support.microsoft.com/kb/834484
I’m wondering if corrupted registry settings for the Windows Installer could cause permission problems that result in an error 1603?
Maybe it can cause the problem seen by Lander (#1334) as well?
We in the EyeX team at Tobii are of course also looking into things at our side, but since error 1603 is a generic and unspecific error it doesn’t give us any clue where to look for a problem. It doesn’t tell us if it is a problem with our installer or if something in the environments of the specific computers have been corrupted.
In the case of Fezile (#1376), it seems it was caused by something that was corrupted in the environment of the specific computer.