Computer Operation/TL (IQ/Easy) is the skill to use a computer.
It is referenced in GURPS Mysteries, p. 110, on its use by investigators.
Note: this is different from Computer Programming
- On its breadth of coverage 
- On its ubiquity in a modern setting , , 
- On differences from Electronics Operation (Computers) 
- On using email 
- On its use with smartphone apps 
- On searching the Internet 
- On its use by a psychokinetic