In 1991, as he moved PC/Computing's headquarters from Boston to Foster City, California, Kolowich took over all of Ziff Davis' electronic publishing efforts, consolidating them under the name Ziff-Davis Interactive. The most notable product of these efforts was ZDNet, an online complement to Ziff-Davis' print publications, which later became the most valuable property in the Ziff-Davis portfolio. In 1994, when the Ziff family disposed of its publishing properties, Kolowich brought the company's online technology division, called the Interchange Online Network, to AT&T, where Kolowich was named president of AT&T New Media Services.