To start up a computer
Boot up
To prepare a computer for use (new or already existing)
Set up
To appear suddenly
Pop up
To insert credentials
Log on/in
To register or create a user account
Sign up
To move upwards and downwards to read
Scroll up/down
To gain anauthorised access to a computer
Hack into
To make a copy of data
Back up
To finish using a computer
Log out/Log off
To enter/type data into a device
Tap in
To fail to operation/crash
Go down
To make space
Free up
To attach to the electricity supply
Plug in