|The error was: an unhandled Win 32 exception occured in iexplore.exe . Possible debuggers: New instance of MS VS2010.|
All this is saying is IE crashed, and Windows wants to know if you want to start up VS to debug it. If the system is really dragging, and it's not the SQL Server Express VS likes to install, you probably picked up a virus.
What is the best way to go about uninstalling VS2010 Beta 2 Ultimate and the .NET framework 4?
Use this tool.