Microsoft CEO Steve Ballmer has said that Windows remains the at the core of the companies growth plan amid slowing personal computer sales across markets.

"Windows is at the center of our ‘go-forward’ strategy," Ballmer said in a presentation.

"We feel very comfortable that this is a smart thing to do for our customers and the smart thing to do for our shareholders."

This year Industry watcher Gartner has lowered its forecast for global PC unit sales twice, citing declining mini-notebooks sales and growing popularity of iPads.

In June the firm revised worldwide PC unit shipments growth to 9.3% in 2011, from 10.5% forecast in March. Gartner had to again cut the forecast for this year saying that worldwide PCs sales will hit 352 million units in 2011, a rise of just 3.8% on 2010 figures.

Growth forecasts for 2012 have also been cut, with Gartner now suggesting growth of 10.9% over 2011 instead of the 12.8% it had previously estimated.

Gartner research director Ranjit Atwal said that the emergence of tablet devices – with Apple’s iPad leading the charge – is having an impact on PC sales besides other factors. "Younger people are looking to more portable devices instead of their desktop counterparts," Atwal said.

However, according to a Bloomberg report, Microsoft has said that developers have alreday downloaded 500,000 copies of the preview version of Windows 8 since its debut a few days ago.

Admitting that the company has difficult times ahead, Ballmer said that it is gratifyinng to see the interest of people in the new OS.

"I’m not saying I love where we are, but I am very optimistic on where we can be," Ballmer said.

"While it’s clear we have a long way to go still with Windows 8, we’ve been gratified by the reactions and the interest."

"The initial reaction has been all we have been hoping for," Ballmer told analysts.

He also added that the company will keep Windows at the heart of its growth strategy.

"Windows is at the center," he said. "People question whether that is a good idea. I think it’s an exceptionally good idea."

Ballmer also assured that the company’s partnership with Yahoo will remain strong in future.