I have a brand new Dell i7 Skylake laptop, brand new Samsung Pro 960 SSD, New Windows 10 build 16299 (Fall Creators Update released yesterday) just upgraded from build 15063.
I downloaded Ubuntu from Windows Store but got this error:
The WSL optional component is not enabled. Please enable it and try again. See https://aka.ms/wslinstall for details. Error: 0x8007007e Press any key to continue...
I googled the recommended site and passed the hex error code with no luck.
Rebooting didn't help.