Uh oh, there could be trouble ahead… Or at least, it looks like there is for Microsoft anyway.

New data from Gartner paints a less than rosy picture of the future for the Redmond firm, whose dominant PC market faces being overwhelmed by consumer’s preference for tablet devices over PCs. According to the research firm, tablet computer sales will outstrip those of PCs by 72% in just three years, with shipments of PCs dropping at ever-faster rates.

Gartner predicts that the market for PCs and laptops will dip by another 7.6% by the end of this year, to some 315 million units in total, with this number set to fall even further every year for the next four years. Meanwhile, the research firm estimates that tablet device sales will surge, with 197 million units sold in 2013 – a growth rate of 69.8% on the previous year – and continue rising for the next four years.

Carolina Milanesi, Vice President of Research at Gartner, explains these projections as follows:

“While there will be some individuals who retain both a personal PC and a tablet, especially those who use either or both for work and play, most will be satisfied with the experience they get from a tablet as their main computing device. As consumers shift their time away from their PC to tablets and smartphones, they will no longer see their PC as a device that they need to replace on a regular basis.”

Gartner predicts that consumers will be so taken with tablet devices, that the market will see some 468 million units sold by the end of 2017, compared to just 272 million PC sales. Driving this growth will be a flood of low cost tablets with improving specifications, something that will see the trend take hold not just in developed markets, but emerging markets as well.

The report suggests a grim future for Microsoft, which derives the vast majority of its revenues from the PC market through its Windows operating system and Office software. Despite making some serious efforts to catch up in the mobile space, the Redmond-based firm has largely failed to penetrate a market dominated by iOS and Android devices. It will of course retain the lion’s share of the declining PC market, but more than anything the report presses home the need for Microsoft to redouble its efforts in mobile if it’s to continue enjoying the same revenues it’s become accustomed to.

This is all presuming that Gartner is correct in its theory that the PC market will continue to decline. While its predictions are usually quite robust, it doesn’t always get things right – back in 2011 it boldly predicted that Windows Phone would surpass iOS by 2015, something that’s almost certainly not going to happen now.

But supposing Gartner is right, Microsoft clearly has much to worry about. Not only would its Windows operating system be affected, but possibly even sales from Office too. Microsoft’s productivity suite still isn’t available on Android or iOS yet, and with the release of Google’s Quickoffice for Android it would face some tough competition to dominate that particular platform.