Lewis E. Platt rose from an entry-level engineer to become the chief executive of Hewlett-Packard. During his tenure as chief of Hewlett-Packard from 1992-99, Mr. Platt was known for his low-key management style, straightforward manner and an engineering attitude applied to the executive suite. In 2005, when Mr. Platt was serving as the lead board member and nonexecutive chairman of Boeing, he quickly began an investigation after receiving an anonymous tip that the chief executive, Harry C. Stonecipher, was having an affair with a company executive. Mr. Stonecipher admitted the affair, and he was asked to resign. Born on April 11, 1941, Mr. Platt grew up in Johnson City, N.Y., and went to Cornell University, where he majored in mechanical engineering, and then earned a master's degree in business administration from the Wharton School of the University of Pennsylvania. After leaving Hewlett-Packard, Mr. Platt served for two years as the chief executive of a much smaller company, Kendall-Jackson Wine Estates. Mr. Platt is survived by his wife, Joan Ellen, and his four daughters, Caryn, Laura, Amanda and Hillary.