Dell Inc.'s slump deepened in its latest quarter as the growing popularity of smartphones and tablets undercut sales of its desktop and laptop computers.

The fiscal second-quarter results announced Tuesday served as the latest reminder of the challenges facing Dell and other personal computer makers as they scramble to adapt to the technological upheaval unleashed by Apple Inc.'s line of sleek devices such as the iPhone and iPad.

The shift to more mobile computing has established Apple as the most valuable company in U.S. history, while businesses that revolved around selling desktop and laptop computers have been struggling.

Dell Inc., the second largest U.S. maker of personal computers, is trying to adjust by expanding into software, technology consulting, data storage and computer servers — all of which produce higher profit margins than selling PCs and printers.

"We're transforming our business, not for a quarter or a fiscal year, but to deliver differentiated customer value for the long term," Michael Dell, the company's CEO and founder, said in a statement Tuesday. "We're clear on our strategy and we're building a leading portfolio of solutions to help our customers achieve their goals."

As part of its makeover, Dell on Tuesday announced a new leader for its division that oversees many of its corporate products, including computer networking and data storage. Marius Haas is replacing Brad Anderson as president of Dell's enterprise solutions. Haas most recently worked at the investment firm Kohlberg, Kravis, Roberts & Co. after previous stints at Dell rival Hewlett-Packard Co. and Intel Corp.

Even if Dell's strategy is successful, the company's evolution will take time. That reality has caused Dell's stock to fall this year while the overall market has been climbing.

In a sign of further weakness ahead, Dell lowered its earnings target by 20 percent for its fiscal year ending in January. Dell trimmed its full-year guidance, even though its adjusted earnings for the just-completed quarter topped analyst projections.

The company, which is based in Round Rock, Texas, tied it its bleaker forecast on "the uncertain economic environment, competitive dynamics and soft consumer business."

Dell shares shed 39 cents, or 3.2 percent, to $11.951 in Tuesday's extended trading following the release of the earnings report.

In its latest quarter ending in July, Dell earned $732 million, or 42 cents per share. That represented an 18 percent decline from net income of $890 million, or 48 cents per share, at the same time last year.

If not for costs unrelated to its ongoing business, Dell said it would have earned 50 cents per share. On that basis, Dell topped the average estimate of 45 cents per share among analysts surveyed by FactSet.

Revenue for the period fell 8 percent from last year to $14.5 billion. That was nearly $200 million below analyst forecasts.

The weakest area was in Dell's mobility division, where revenue plunged 19 percent from last year. PC sales decreased 9 percent from last year.

Dell's lackluster performance is expected to be mirrored by HP Wednesday when the world's largest PC maker is scheduled to release its quarterly results. HP already has warned its quarterly loss will approach $9 billion because of an accounting charge to reflect the diminished value of a past acquisition.