Q:

WSL is enabled on windows 10 but Linux.exe errors that it is not enabled

When I run ubuntu1804.exe for having "Linux distros for WSL", I receive this:
The Windows Subsystem for Linux optional component is not enabled. Please enable it and try again.
See https://aka.ms/wslinstall for details.
Press any key to continue...

But, it is enabled on my Windows:
PS C:\WINDOWS\system32> Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux

Path          :
Online        : True
RestartNeeded : False

And here is the screenshot of optional features window:

What sould I do to solve this? would appreciate any assistance.
P.S: I tried "disabling WSL, rebooting, Enabling WSL, rebooting" but not working.

A:

My windows version and also Windows Subsystem version is OLD so it is not compatible.
It must be upgraded.

