Guy returned to Oklahoma State in 1995 as the Cowboys linebackers coach. From 1998 to 2000, he served as defensive coordinator at Boise State before taking a similar position at Arizona State. During his time at Boise State, the Broncos won 2 conference championships, the first Division-1 conference championship in school history. Guy was responsible for running a defense that was 1st in total defense, scoring defense, and rush defense both years. Boise State went on to win back to back Humanitarian Bowl Games during that time.