Krol was born August 21, 1951, and raised in Chicago, Illinois. He received his B.A. from the University of Illinois and spent his entire career there.

In 1985, he began working at the National Center for Supercomputing Applications. Indeed, "Ed Krol was the network manager for the NCSA when the contract was received to establish the NSFNet, and led the team in the network development" [1]. During this time, he published (through funding by the National Science Foundation), the 1987 popular user's guide Hitchhiker's Guide to the Internet. In 1989, he became the assistant director for Network Information Services, Computing and Communications Service Office, University of Illinois.

In 1992, he published the popular user's guide to the Internet, The Whole Internet User's Guide and Catalog, which was noted by the New York Public Library as one of its Books of the Century in 1995.[2][3]