I had the same problem , first I couldn't find those dlls
in the list of .NET components
. but later I figured it out that the solution is :
1- first I changed target framework
from .NET framework 4 client profile
to .NET framework 4
.
2- then scroll down the list of .NET components
, pass first list of system.web.
.. , scroll down , and find the second list of system.web.
.. at the bottom , they're there .
I hope this could help others