Silverlight, Why Do You Taunt Me So?

Silverlight steadfastly refuses to install on my development Tablet PC or in my "Orcas Beta" Virtual PC. Those are the only two machines on which I'll put an under-development CLR, since experience has shown that it can be very difficult to cleanly uninstall anything in Microsoft's browser-CLR-plugin axis. This is a shame, because I have some ambitious Silverlight projects.