Wednesday, December 9, 2009

Installing WPF Toolkit June 2009 on Windows 7 (getting rid of the heinous "WPF Toolkit requires .NET Framework 3.5 SP1")

Lately I've started to try out Windows 7 on my main development machine at work, this has worked really well and I'm really loving the Windows 7 experience... However there is always a darkside to everything, apparently the version of .NET Framework 3.5 SP1 that comes bundled with Windows 7 has a different version number than the regular download and thus you will bump into the following type of errors:

Imaging my frustration when googling around for this and not finding anything particularly useful (it's a rather annoying error message given the fact that it isn't correct since .NET Framework 3.5 SP1 is on the machine). Anyway after some email correspondance with a friend and colleague (thanks Samuel) my attention was turned to the Microsoft Platform SDK which contains a little tool called "Orca" which let's you inspect and modify the tables in an .msi file.

If you don't want to install the whole platform SDK you can grab the setup for "Orca" from my sky drive.

Now for the magic, to get around the error message we need to nuke the launch condition in question from the .msi file (there might be an easier way todo this so feel free to correct me by leaving a comment):

Step 1, Launch Orca.
Step 2, Open the .msi package.
Step 3, Find & select the launch condition entry in the navigation pane.
Step 4, Select NETFX35SP1_INSTALLED in the details pane & right click.
Step 5, From the context menu select drop row.
Step 6, Confirm the removal of the launch condition.
Step 7, Save the .msi package.
Step 8, Run the .msi package and voila no more error message.


  1. Peter - You are a legend. This solved my problems and worked perfectly.

    I was originally trying to install Expression Studio with SketchFlow. This had a silent fail and gave no real error. I then inspected the error logs to notice the fail was related to WPF.

    You can imagine my joy when the WPF installer then failed due to the SP1 bug. Your workaround will help a lot of people.

    Great post and thanks again,

  2. Connor,

    Thanks for the kind words, it's allways good to know that someone else benefited from a post.