actually there newer version 4.5 for .net framework
the link :
http://msdn.microsoft.com/en-us/library/5a4x27ek.aspx
u can download web installation or stand alone (redistributable) from there..
edit: the 4.5 also contains what in 4.0 so it advaised to install the 4.5
btw OP. u had two identical thread close one or merge them.....