A: No. .NET Framework 3.5, 4.x, and 5+ (Core) run side-by-side. They do not conflict.
When Microsoft released .NET Framework 3.5, they created a single installer that contains the complete payload for all three versions. Therefore, enabling or installing .NET Framework 3.5 automatically installs and enables 2.0 and 3.0 components.
The full offline package requires that the source files for Windows features are available during installation. On modern Windows 10/11, running dotnetfx35.exe alone may still attempt to download missing components from Windows Update. To force a truly offline installation, you need to use the deployment image servicing and management (DISM) tool with the original Windows installation media. Net Framework 3.5 Includes 2.0 And 3.0 Download Offline
: Type the following command, replacing D: with your actual drive letter: Dism /online /enable-feature /featurename:NetFx3 /All /Source:D:\sources\sxs /LimitAccess
: Use the Microsoft .NET Framework 3.5 SP1 (Full Package) from the Official Microsoft Download Center. When Microsoft released
To recap:
By default, Windows attempts to download the necessary files for .NET 3.5 from Windows Update servers. While this works for most users with stable internet, it is prone to failure. On modern Windows 10/11, running dotnetfx35
Because they share the same base, you cannot run 3.5 without 2.0 and 3.0 being present; hence, Microsoft bundled them into a single installer. Why Use an Offline Installer?
After your offline installation, verify success: