Michael Dell
Michael Dell

After building a disruptive business model to sell personal computers in the '80s and '90s and then seeing that model lose steam, Michael Dell, now 47, came back as the CEO in 2007. He's helped rejuvenate the business, leading its transformation to a broad-based infotech company.

By John A. Byrne, contributor @FortuneMagazine - Last updated March 22 2012: 6:02 AM ET
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