I bought a new laptop and installed the Riot launcher, but League of Legends says .NET Framework 3.5—including .NET 2.0 and 3.0—is required. The built-in installer fails every time with "The parameter is incorrect" and error code 0x80070057. I also tried downloading .NET 3.5 separately, but that produces the same error. The .NET 3.5 option appears to be turned off in Windows Features. What is the best way to install or repair it?
2 Answers
You can try Microsoft’s official .NET Framework 3.5 download instead of letting the game launcher handle it. Make sure you use the installer intended for your version of Windows and run it as administrator. If that gives the same error, the Windows component store may be damaged rather than the download itself failing.
Because .NET 3.5 is a Windows feature, enable it through “Turn Windows features on or off” and select the option for .NET Framework 3.5, including the 2.0 and 3.0 components. If Windows cannot enable it, repair the existing .NET installation and then restart the computer before trying again. Running Windows Update first can also provide the files needed for the feature.
I checked Windows Features and the 3.5 option is currently turned off, but enabling it fails with the same message.
I tried the official installer too, but it still returned the same 0x80070057 error.