H.P.’s news, for example, comes on the heels of surprising plans announced last week to cut about 5 percent of the work force at the network computing company Cisco Systems and continuing issues at giant tech companies like Oracle, Intel and even Microsoft.

If there is a common thread among these older outfits, long considered bellwethers for their industry, it is that they are all struggling to adapt to a computing world where people use the Internet on mobile devices like smartphones and tablets. Likewise, the information they retrieve is stored in a cloud of network computers that are used by many companies at the same time.

In some cases, they are big makers of things like personal computers, which people are not buying as quickly as they once did. In other cases, they are making costly corporate computing equipment like routers, which direct traffic on Internet networks. Those routers are still in demand, but they don’t typically attract the prices they once did.

“All the traditional enterprises are in a pickle,” said Krish Ramakrishnan, a former general manager at Cisco who now runs Blue Jeans Network, a cloud-based videoconferencing service. “They want to have cloud businesses, but each of their divisions will have to transform differently.”

For H.P., a leader in personal computers, printers and computer servers, as well as data storage and networking, sales were down in almost every business. Total revenue was $27.2 billion, down 8 percent from a year earlier. Net earnings were $1.4 billion and, excluding special charges, were about 15 percent below their year-ago level. H.P. stock, which fell 1.8 percent in regular trading on Wednesday, dropped 6 percent more in after-hours trading.