If you are running Windows 10 and need to install something old that requires .NET 2 or .NET 3.5 you will likely follow the instructions to install it from PROGRAMS AND FEATURES > TURN WINDOWS FEATURES ON OR OFF > .NET FRAMEWORK (INCLUDES .NET 2.0 and .NET 3.0) but then find you receive errors like 0x800F0906 and 0x800F081F . This is frustrating. Fortunately the solution is simple IF you have a Windows 10 source disk:
You can install .NET 3.5 by bringing up a CMD window (don’t forget to right click and RUN AS ADMININISTRATOR) and then type either:
Dism /online /enable-feature /featurename:NetFx3 /All /Source:<drive>:\sources\sxs /LimitAccess
This has been a problem since Windows 8 and Microsoft really needs to fix it. I have to do this command line install 100% of the time I need old .NET versions.