By MICHAEL LIEDTKE and PETER SVENSSONSAN FRANCISCO (AP) â¿¿ The ailing personal computer market is getting weaker, and it's starting to look as if it will never fully recover as a new generation of mobile devices reshapes the way people use technology. The latest evidence of the PC's infirmity emerged Wednesday with the release of two somber reports showing unprecedented declines in sales of desktop and laptop machines during the first three months of the year. As if that news wasn't troubling enough, it appears that a pivotal makeover of Microsoft's ubiquitous Windows operating system seems to have done more harm than good since the software was released last October. "This is horrific news for PCs," said BGC Financial analyst Colin Gillis. "It's all about mobile computing now. We have definitely reached the tipping point." First-quarter shipments of PCs fell 14 percent worldwide from the same time last year, according to International Data Corp. That's the deepest quarterly drop since the firm started tracking the industry in 1994. Another research firm, Gartner Inc., pegged the first-quarter decline at 11 percent. The deviation stemmed in part from the firms' slightly different definitions of PCs. No matter how things are parsed, the PC market is in the worst shape since IBM Corp. released a desktop machine in 1981. PC sales have now fallen from their year-ago levels in four consecutive quarters, a slide that has been accelerating even amid signs that the overall economy is getting healthier. PCs are going out of style because they typically cost more than smartphones and tablets, and aren't as convenient to use. Most PCs sell for $500 to $1,500 while the initial out-of-pocket expense for a smartphone runs as low as $99 while an array of tablets sell for $200 to $300. Apple's late CEO Steve Jobs, whose company propelled the mobile computing revolution with the 2007 release of the iPhone, declared that the world was entering a "post-PC era" shortly after the iPad came out three years ago.