A couple of days ago I expressed my disappointment about the beta 2 version installers of the Entity Framework installers not working with Visual Studio 2008 RTM. Soon after my initial post I blogged about a quick and dirty workaround which involved "hacking" the Entity Framework installer. Thanks to a comment submitted by James Story the following solution will allow you to install the Entity Framework Tools CTP with Visual Studio 2008 RTM.

Please be aware that the ADO.NET team is planning to release an updated version of the Entity Framework which will work with Visual Studio 2008 RTM, soon - according to an email from Scott Guthrie. So while these workarounds get you started, you should regularly check the ADO.NET Team's blog.

In order to install the Entity Framework Tools CTP you have to change a signature in the installer. In order to do so you need the Orca tool burdened in the Core Platform SDK. Aaron Stebner (in general a great resource when it comes to installation issues with a whole list of Microsoft products) provides a direct download link to the utility. Once downloaded and installed open the dp_entitydatamodeltools.msi installer via File > Open.

Select the Signature table and change the MaxVersion of the DP_VS90DEVENV_FileSearch entry to 9.0.21022.8 (the one of the Visual Studio 2008 RTM) as depicted in the following screen capture:

Don't forget so save and you're done.

Please note that some features of the tools might not work with the final version of Framework 3.5, so once the updated Entity Framework and Tools are out, you should uninstall this CTP and update to the newer one!