Installation of Dynamics NAV 2009 hangs during installation of Outlook Add-in

When installing NAV 2009 RTM you can sometimes if you are unlucky end up with an installer that hangs when installing Outlook Add-in. The most common reason for this is that the installation is not able to update the” Outlook.exe.config” file and get stuck in an infinitive loop.
When looking in the event viewer you will get a similar error message to this:

Product: Microsoft Dynamics NAV 2009 Outlook Add-in — Error 27519.Error updating XML file C:Program FilesMicrosoft OfficeOffice12Outlook.exe.config. -2147024891

The problem is that the file is read-only or for some other reason is not accessible. To fix this problem in short words, simple search for “Outlook.exe.config” and make the file not read-only. The “Outlook.exe.config” is hidden, so the easiest way to change the property of the file is to search for it with explorer and under “More advance options” select “Search hidden files and folders”. The installation will directly after you have changed the property continue.

This problem will be fixed in NAV 2009 SP1 when it’s released later this year.