Download an older version of Firefox

You can find the older versions here

https://ftp.mozilla.org/pub/mozilla.org/firefox/releases

Open an Explorer Window from CMD on Win7

You can use explorer or start

Show the number of lines added and removed by an author in Git

Disable screen orientation hotkeys on Windows 8 on Dell XPS 12

AltGR + Arrow keys rotate the screen, to turn this off do a CTL + ALT + F12. This will bring up the 'Intel HD Graphics Control Panel', goto 'Options' and disable 'Hot Keys'.