(1)Clean your existing .net versions using .net framwork clean up utility (if any)
http://blogs.msdn.com/b/astebner/archive/2008/08/28/8904493.aspx
(2)and download and install standalone installer.. .net framework 4 and install it
http://www.microsoft.com/en-us/download/details.aspx?id=17718
(3)additionally if it is still prompting you can hide the windows update..
http://technet.microsoft.com/en-us/magazine/ff382716.aspx
-----------------------------------------------------------------------------------------------
Hetti Arachchige V Aravinda | Microsoft
Community Support | Windows Tech Information
(B.Sc, Microsoft Small Business Specialist, Dip. in Network Administration, MCP, MCTS,
MCSA, MCSE, MCITP, CCNA, MBCS)
-----------------------------------------------------------------------------------------------
Don't forget to mark this as helpful if you found this is helpful ,and its the answer mark this as answer.
-----------------------------------------------------------------------------------------------