Apple Inc.'s computers are the most reliable and its support the most dependable of the five top vendors, a national chain of computer service shops said today.

Macs beat machines built and sold by Lenovo Group Ltd., Hewlett-Packard Co., Gateway Inc. and Dell Inc., according to Rescuecom Corp.'s second annual reliability report. Apple, which took the second spot last year, blew away the competition this year by posting a score of 51% higher than next-best Lenovo.

To come up with its scores, Re...