Uninstall Tool for the latest WinFX CTP (Feb 2006) has been released. It allows you to uninstall all the WinFX Runtime Components 3.0 Beta 2 bits in the right order using one uninstallation application. There is no need to go to Add-Remove Programs and look for all the entries. It also can remove a Beta of .NET Framework 2.0 which the old CTPs were running on and Visual Studio 2005 Extensions for WinFX Runtime Components 3.0 Beta.
You can download the tool from http://go.microsoft.com/fwlink/?LinkID=54981