Walker very rarely (if ever) touched a computer, and didn't even have one on his desk. He always relied on Trevette to do the computer research in a case.
Ranger Jimmy Trivette:
Yeah, right. If I'd get an ear pierced, Walker'd make me ride in the back of his truck.
In the Pilot of the series, CD says he was a ranger 5 years. But in season 2, Alex asks him how long he was a ranger for and he says "28 years"