Microsoft will lift the lid on its first specialised OS for tablets during two separate conferences that kick off on May 31, Bloomberg reports.

Though Microsoft has previously demoed Windows 7 running on tablets, the claim is that the firm will, for the first time, unveil a platform specifically designed to take advantage of such devices.

The question is, which OS will it be?

Two for one

Sources privy to the 'confidential plans' have told the site that Windows president Steven Sinofsky will do the honours at the D9 Conference in California, while VP Steve Guggenheimer takes to the stage at Computex in Taipei.

It's believed a Nvidia Tegra equipped tablet will be used in the demonstrations.

Previous speculation has hinted at a modified version of Windows 8 – which, it's believed, will be delivered in multiple form factors at release – will spearhead Microsoft's assault on the tablet market.

However, the possibility of Windows Phone 7 making an appearance remains on the cards, particularly in light of Microsoft's recent press blitz for the 500 feature strong Mango update, due to roll out this autumn.

[source: Bloomberg]