I have gotten a couple of questions from customers this week who have installed the final release of the .NET Framework 2.0 and then have had trouble trying to install the WinFX September CTP. The underlying issue here is that the WinFX September CTP requires the beta 2 version of the .NET Framework 2.0 (v2.0.50215.xx), but the final release of the .NET Framework 2.0 cannot co-exist on the same machine as the beta 2 version of the .NET Framework 2.0.
You will note that if you have the .NET Framework 2.0 beta 2 installed and attempt to install the final release, you will get an error message stating that you need to uninstall beta 2 first. However, the setup package for the .NET Framework 2.0 beta 2 has no knowledge about the final release of the .NET Framework 2.0 (since it shipped earlier and we cannot predict the future), and therefore beta 2 setup will not block. Instead, if you try to install beta 2 on a machine with the final release already installed, it will fail with various possible error dialogs. The most common error I've seen so far is the following:
Error 1920.Service '.NET Runtime Optimization Service v2.0.50215_X86' (clr_optimization_v2.0.50215_32) failed to start. Verify that you have sufficient privileges to start system services.
If you want to use the WinFX September CTP on a machine that already has the final release of the .NET Framework 2.0 and/or VS 2005, you have a couple of options:
Uninstall the final release of the .NET Framework 2.0 and/or VS 2005, then install the WinFX September CTP (which will automatically install .NET Framework 2.0 beta 2 for you)
Install the WinFX September CTP on a separate machine that does not have the final release of the .NET Framework 2.0 or VS 2005 on it
Wait for the next WinFX CTP that will be based on the final release of the .NET Framework 2.0. Unfortunately, I don't know for sure when the new CTP will be released, but it should be soon...
I apologize for any inconvenience that this scenario is causing....
<update date="11/29/2005"> There is a November 2005 CTP for WinFx now available that works with the final release of VS 2005. Check out my new blog post for additional information </update>