Blend 4 breaks VS2010 for Silverlight

I had VS2010 running fine with Silverlight development. Then I installed Expression Blend 4. Now when I run VS2010 and try to debug a silverlight app I get an error saying "Unable to start debugging. The silverlight developer runtime is not installed. 开发者_C百科Please install a matching version." I've tried uninstalling silverlight tools, and reinstalling them from scratch (the latest april version). But I still get the same message. So basically I'm now unable to do VS2010 SL development. I'm on the verge of just rolling back to my last system restore point and giving up on Blend. But if I do that I'd be worried that Product Activation would never allow me to reinstall it in the future, since the MSDN download page implies I'm only ever allowed to install it on a single machine. Any help appreciated.

Thanks

I had the same problem after installing Expression Studio 4. I installed the Developer version of Silverlight at: http://go.microsoft.com/fwlink/?LinkID=188039

and the problem seems to be resolved.

Hope that helps.

Try reinstalling or reparing the Silverlight_Tools for Silverlight 4.

You tried that.

The product activation system isn't that draconian it has to allow for things like hardware failures etc which would require re-installs.

Thanks for the suggestions. I solved it this way: Since I'm running under parallels, I rolled back to a snapshot taken before I'd installed Blend. Then I rebooted Windows. Then I reinstalled Blend (happily with no draconian activation problems!), and everything worked.

So why did it work the second time and not the first time? The first time I installed Blend, I'd shut down VS2010, explorer etc, but not rebooted. Perhaps some hidden VS-related process was still running. Installing Blend in that situation screwed everything up, and removing and reinstalling stuff didn't fix it. Obviously the Blend installer should have spotted the dangerous process and taken remedial action, but it didn't. Perhaps MS recommends you reboot before installing new software? That would be a bit of a nuisance, and I've never needed to before. My real lesson from this is to work in a VM and take regular snapshots.

Thanks again.