I was playing Minecraft on a friend's PC the other day and noticed that when I pressed Shift + Click on an item in a chest, it automatically went to my inventory. How do I enable that on my own PC?
This is a normal Minecraft feature. If it's not working on your PC, chances are you have touch screen mode enabled. You can disable it through controls > touch screen mode.
Note: If touch screen mode is enabled, holding Click and dragging items work in place of Shift + Click.
This is a normal Minecraft feature. Have you tried it on your PC? If it doesn't work there, then something is wrong with your setup.
This is a feature of Inventory Tweaks. It comes with this feature, and much more. You will need Minecraft Forge, though.