I dived straight into the Silverlight 2.0 Beta 2 download, and soon hit this dialog:
I discovered that I should have read this guide to installation by Microsoft’s Bradley Bartz. It is a little arduous: remove KB949325 (which requires the Visual Studio installation media) as well as any previous Silverlight SDK and tools, apply Visual Studio 2008 SP1 Beta if you have not yet done so, then install Silverlight. Otherwise you may get an error relating to silverlight_uninstallrtmpatches.exe as I did.
I’m grateful to BradleyB. I admit, the issue is also noted on the download page:
If you have previously installed Silverlight Tools Beta 1, you must uninstall KB949325 before installing Visual Studio 2008 SP1 Beta.
I should have read it more carefully.
In my case, it was worse than that. I could not find KB949325 in the list of installed programs, but the Visual Studio SP1 Beta install still failed. I found this post by Heath Stewart. I had to follow the manual steps with reg.exe; the utility did not work for me. I also found that KB945140, which is the SP1 Beta, was actually listed as installed in Programs in Control Panel, but only for the Visual Studio 2008 Shell (Integrated mode). I removed that too. Eventually, SP1 Beta installed successfully, following which the Silverlight SDK and Blend 2.5 installed without further issue.
Stewart has not responded to Will Dean’s comment on his post:
It sometimes feels that VS + .NET FX are in a death-spiral of an ever-increasing prevalence of this sort of issue.
For more evidence, see Aaron Stebner’s worrying posts about problems with the installation of .NET Framework 3.5 Client Profile. Apparently this beta, once installed, makes it hard to install other versions of .NET or applications which depend on them; and uninstall is a multi-step process that has to be done in a certain order.
The only positive thought I can muster from all these complications is that this is the kind of issue that running apps in the browser avoids, at least for users rather than developers. That assumes that the install for the Silverlight runtime is bulletproof; I’ve been impressed with it so far, though I’ve heard of some users having problems. The Flash runtime isn’t immune either; I’ve had issues installing the latest security update and resorted to Adobe’s Flash uninstaller.