Installing .Net 3.5 in Windows 8

I don't know why I have to separately install .net 3.5 in Windows 8 to make some apps work. I needed to install Windows Live Writer to write some posts but I couldn't because the damn .net 3.5 could not get installed. Actually there is some problem with my 3g router and I am unable to access Windows Update. So whenever I try to install Windows Live Writer I get the prompt to install .net 3.5 through Windows Update but that doesn't work since I cannot access the WU server. So I read some articles on how to manually install .net 3.5 using the Windows 8 DVD through CMD and using DISM. So I mounted the ReleasePreview ISO of WIndows 8 that I had and tried to install .net 3.5 using command line. But even that doesn't work and I get a error that source could not be found. I used the exact steps on this guide ( and it still doesn't work. Any ideas? Okay so I found a solution and editing this post to include the same: Go to this link: Download and install a tool that it says at the bottom which is pretty easy to use. This solved the problem for me.