Help with viewing flv and mkv file formats

Hi there, I need help viewing files with flv and mkv extension using the F7 key.
I am using Windows 10.. Please advise.

Thank you.

What exactly do you mean by viewing those files? Playing them, without double click or pushing Enter?

FLV in the viewer pane (F7) will require you to install a codec and splitter, unless it is already working in Windows Media Player.

MKV may work out of the box in Windows 10 and above, but may also require some configuration.

Unfortunately, video software is complicated and fragile, but this guide has lots of suggestions: