How to fix installation error for .Net?

I am receiving an error when trying to install Solidworks (screenshot attached).

I am running Win 7 64-bit. SW has run fine with this Windows install before, so I am unsure of the issue. I checked in control panel, and I have .Net 3.0 and it is enabled. I tried to download and install .Net 4.0 or higher, but Windows always says that it is up-to-date when I try.  Please help!

Thanks!

Dan

SolidworksGeneral