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Michael Dell (Dell Inc.)
Michael Dell (Dell Inc.)
Dell founder and CEO Michael Dell
Retired 2004, returned 2007

Twenty years after he founded the company in his dorm room, Michael Dell ceded control to Kevin Rollins, a former Bain partner. Under Rollins' watch, the company faced a slew of challenges: customer service complaints, growing competition from HP, and an SEC investigation into its accounting. When Rollins resigned in 2007, Dell returned to attempt a turnaround.

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Last updated February 17 2009: 1:35 PM ET
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