If your MacBook Pro is from 2009 u can't upgrade to high sierra. 30 years ago Apple had HFS now Apple finally updated to Apple File System or (APFS). Now the new APFS has a 64bit data structure & it is safe & secure with crash protection, safe document saves, stable snapshots & native encryption. Also with High Sierra, it is more responsive. Some new features it has are Instant file & directory cloning, fast directory sizing etc.. Next on the new OS u have the new standard for video formats & it is H.265 High-Efficiency Video Coding. Also with the new video format, it saves up to 40% better compression than the old version. One of the Coolest Keyboard Shortcut ever. I have been trying to figure it out finally did yes. Take a screenshot of part of your screen Press Command-Shift-4. The pointer changes to a crosshair pointer. Move the crosshair pointer to where you want to start the screenshot. Drag to select an area. While dragging, you can hold the Shift key, Option key, or Space bar to change the way the selection moves. This also works if u want to screenshot menu's The picture below was done by doing command + shift + 4 Screenshot the whole computer. Finally is Command + Shift + 3 for a selection.