Where it is installed
.NET Framework 3.5 runs on CLR 2.0, not the CLR 4 of .NET Framework 4.x: an app built for it needs 3.5 installed, or a <supportedRuntime version="v4.0"/> entry in its config file to run on 4.x. On Windows 10 and 8.x it ships as an optional Windows feature that must be turned on (Turn Windows features on or off).
FAQ
When does .NET Framework 3.5 support end?
January 9, 2029.
What C# version does .NET Framework 3.5 use?
C# 7.3 by default. Newer language versions can be set with LangVersion, but features that need runtime support (such as default interface methods) do not work on .NET Framework.
What is the target framework moniker for .NET Framework 3.5?
net35.
When was .NET Framework 3.5 released?
November 19, 2007.
Other versions
- .NET 10
- .NET 9
- .NET 8
- .NET 7
- .NET 6
- .NET Core 3.1
- .NET Framework 4.8
- .NET Framework 4.7.2
- .NET Framework 4.6.2
- .NET Framework 3.5
- All versions and the checker