Downgrading from 4.8 version of .NET framework to 3.5.1

Question

I provisioned a new Windows 10 64-bit machine and immediately installed VisualStudio on it. During this installation it prompted me to install some .NET related dependencies.

Running:

C:\Windows\Microsoft.NET\Framework\v4.0.30319> .\MSBuild.exe -version

looks like 4.8.37520 is whats installed currently.

I am now trying to install another tool that requires .NET 3.5.1 installed.

So my thinking here was:

1. Uninstall v4.8.x
2. Download and install v3.5.1

So I go to Add or remove programs and type in ".NET" in the search bar and the only item that crops up is:

"Microsoft .NET Core SDK 3.0.100 (x64) from Visual Studio"

So now I'm at a total standstill: do I have 4.8.x installed, or 3.0.100? How does one properly downgrade from 4.8.x to 3.5.1?

Solution

.NET 3.5 is an add-on, it is not included in .NET 4.x. Just leave 4.8 alone, and also install 3.5.

Comments

[Ramhound]

You cannot downgrade.NET Framework 4.8 on Windows 10 version 1903 and 1909 to .NET Framework 3.5. .NET Framework 3.5 on Windows 8+ is a Windows Feature it cannot be installed any other way. .NET Framework 4.5+ is built into Windows 8+. What version is built-in entirely depends on the build. The built-in version cannot be uninstalled. What you specifically have asked to do is not possible.

[Ramhound]

Possible duplicate of Can't install .net 3.5 on Windows 10

[hotmeatballsoup]

Hmmm thanks @Ramhound (+1) however according to this article I can install 3.5 on Windows 10.

[Ramhound]

I never said you could not install 3.5 on Windows 8+. See the duplicate for the correct method. The article also indicates the method. However, you have asked how to replace 3.5 with 4.8 which is NOT possible.

[izzy]

@hotmeatballsoup yes that article looks like a good place to start. If it is not able to work for some reason, the next thing I would try is to download the installer from Microsoft: microsoft.com/en-us/download/details.aspx?id=22

[Ramhound]

The installer you have linked to is incompatible with Windows 8+

[izzy]

@Ramhound Oops, thanks for the correction. Now that you mention it, I guess our domain admin always uses the Windows install media for this, rather than a file.