CharlieArc said:dentaku said:*snip*
copy-paste from someone more knowledgeable than me
Please try the steps at http://blogs.msdn.com/amit_chopra/archive/2010/05/04/uninstall-issues-with-the-mix-ctp-drop.aspx to see if they help unblock you in this scenario.
If they don’t, then you can try the tool at http://blogs.msdn.com/b/astebner/archive/2009/04/10/9544320.aspx as a last resort.
Microsoft should really review their installers. It is designed poorly. I guess their management teams are not aware of this at all. I am very interested at looking at Windows phone 7 but they just try to make everyone's life harder.