Yes, the update (net. framework) is only working on Win 7 64 bit Version, not on 32 bit ... i have the same problem because i use a 32 bit Windows 7 and the net framework 4.6.1 is only for 64 bit....
Yesterday i have found a solution, i have update my 32 Bit Windows 7......Search on Google for Service Pack 1 for Win 7 32 or 64. Installing this and now i can use the newest net.Framework...i hope i could help you guys sorry for my bad english