Today I decided to upgrade to the Beta of the Windows Phone Developer Toolkit, however the uninstall process wasn’t working. It kept asking me what I wanted to install every time I choose the uninstall radio button.
So after a couple failed attempts at uninstalling in different ways, I decided to go to the source, in my case that was:
C:\Program Files (x86)\Microsoft Visual Studio 10.0\Microsoft Visual Studio 2010 Express for Windows Phone CTP – ENU
After in the folder, I just had to right click on the vs_setup.msi file and select Uninstall, after that the process worked like a charm and I could then install the beta. Hope this helps someone besides me.