Apple's iPad and other tablets are causing consumers to delay laptop purchases, Gartner said Wednesday as it downgraded PC shipment projections.

PC sales are still growing - just not as fast as the Gartner analyst firm originally anticipated nor as fast as companies like Microsoft would hope.

"PC shipments are expected to grow 9.3% in 2011, reaching 385 million units," Gartner said in a press release. "This is slightly lower than Gartner's previous projection of 10.5% growth for this year." 

Apple has been selling nearly every iPad it can produce. Tablet sales may also pick up as new Android devices hit the market. RIM is heavily pushing the BlackBerry Playbook, HP is coming out with the TouchPad later this year, and Microsoft is starting to push the next version of Windows as a tablet OS.

Consumers have lost interest in netbooks - or "mini-notebooks," as Gartner calls them - and are seeing fewer compelling reasons to replace their desktop and laptop PCs, particularly during a period of economic uncertainty, Gartner said. The Japanese market in particular will take a hit because of the earthquake and tsunami, with PC growth in 2011 slated for only 2.4%.

Direct substitution of tablets for PCs "will be minimal," Gartner said. Still, "Media tablets, such as the iPad, have... impacted mobile growth, ... because they have caused consumers to delay new mobile PC purchases rather than directly replacing aging mobile PCs with media tablets," Gartner research director Ranjit Atwal reports.

In the long run, PCs will be less a "one-size-fits-all computing platform" than a specialized device "prized for its ability to complement other devices," Gartner said. "PCs will no longer be a market by themselves, but part of a larger device market that ranges from smart televisions to the most-basic-feature phones."

So why are PC sales growing at all this year? It is businesses, rather than home users, who are driving growth.

"Throughout much of the last decade, PC unit growth was powered by consumers," Gartner said. "Over the next 18 months, PC growth will be supported by healthy professional replacements."

Businesses reduced PC spending during the recession, but are now increasingly making the switch from Windows XP to Windows 7 while replacing aging machines. (See also: 11 tools for Windows 7 migrations.)

While Microsoft has sold 350 million copies of Windows 7, Mac sales have been growing faster than Windows sales and Apple has passed Microsoft in market cap and profit.