While trying to install VS 2010 RC on my windows XP sp3 machine, I was facing this issue that the installer wasn't able to install any of the components after it installed .Net Framework 4.0. Once I installed .NET Framework 4.0, it prompted me to restart the machine, and on restart nothing really happened (though the setup was expected to resume). I re-clicked the setup and still nothing happened.
So after trying to re-install VS 2010 a couple times, I found out the solution to the problem -
Display the language bar at the taskbar, right-click on it and choose settings. Then remove the hand writing support from the list. There is a bug in the RC for computers with touch screens.
Here is where I found this: http://social.msdn.microsoft.com/Forums/en-US/setupprerelease/thread/dbcdcd52-d162-4460-9920-33c9ab54b36f