Microsoft's upcoming Surface tablets will directly challenge iPad's dominance, according to company chief executive Steve Ballmer, stressing too that the device and Windows 8 will lead to "epic year for Microsoft."

In an interview published Sunday by U.S. newspaper The Seattle Times, Mr Ballmer has reiterated that Windows 8, which represents the software giant's biggest product push to date, will realise all the projections that were attributed to it.

His optimism, he added, is anchored on the general state of the global PC market, which has been suffering sluggish sales in the past few years due to the constant rise of mobile computing that is best represented by record sales of Apple and Android handsets.

Global consumers, according to data provided by various research firms, were more inclined to spend their cash on smartphones and tablet computers through the next four years but Mr Ballmer remains unfazed.

The worldwide PC market, he told The Seattle Times, "is a big market and Windows 8 will propel that volume."

By next year, the Microsoft CEO added, "there's going to be close to 400 million PCs sold."

Mr Ballmer is equally confident that this firm's latest hardware venture will bring in positive results despite the reservations raised by some analysts and by Microsoft's OEM partners, which were surprised by the company's decision to release the Surface tablets.

The product, Microsoft said, is geared for two markets, with the Intel-powered device poised to attract professional buyers while the one designed to run on ARM chips is set to lure mass-market buys.

Surface's core strength, according to Mr Ballmer, is its ability to meet the overall mobile computing needs of global consumers while at the same time providing an affordable platform to extend their productivity.

The Surface on Windows RT for one is superior over Amazon's Kindle Fire and other 7-inch tablets, Mr Ballmer said because they're not just good enough products.

Buyers will strongly consider the Surface on price concerns as Mr Ballmer hinted that the new Microsoft product will carry price tags that were aimed to hit "the sweet spot."

He gave a likely price range of between $US300 and $800, which effectively belied earlier rumours that the ARM-powered Surface will be priced at around $US199.