My brother has run out of space on his laptop hard drive (750GB) and was wondering if he could transfer over steam games to an external hard drive, or would he have to buy a new internal one and clone it.
Okay you can...so long as you aren't going back and forth with the HDD between computers. Just do it once and move the files permanantly.
So would he not be able to take it out?
Yes but he won't be able to use it on multiple computers...which is really one of the main uses of an external hard drive
oh okay
You can back up your steam games quite easily. Just google that.
Keep in mind that 1TB 2.5" hdds are thicker and might not fit into a laptop.
If i was you, i'd just buy an external hdd, and back up, then remove the games he doesn't use often. Same with movies, music etc.