(Image Source: AllThingsD ) BY KERRY LEARY   ANCHOR MEGAN MURPHY   The war continues between Microsoft and Apple... and this time, it’s because an analyst from Morgan Stanley figured out the rather large amount of money Microsoft is missing out on by not launching iOS-capable Microsoft Office. And by rather large, well, we mean $2.5 BILLION. Fortune plans out how exactly the analyst got to that number . First, he estimates Microsoft sold fewer than one million windows-based tablets last year. He also reports 3 0-40% of Mac users install paid versions of Office on its computers. After all of that number crunching, a rough estimate of 200 million iPads will be sold in 2014. If each Office for iPad is sold for around 60 bucks, there’s the amount-- 2.5 billion extra in revenue every year. But a writer for Forbes says, not so fast. “Microsoft is simply not going to do [this] at a time when it is trying to get Windows 8 off the ground, attempting to gain traction for its Surface tablet line (which include a version of Office) and watching PC unit sales get cannibalized by tablets in general and the iPad in particular.” MacObserver says , Mac users have already survived this long without Office, so the profit may not be as big as analysts are estimating. “After three years on the market, many iOS users have discovered alternatives to Microsoft’s productivity offering, and the absolute ‘need’ for Office is not as strong as it was when the device first launched.” But the article goes on to note Microsoft could benefit from all of the businesses that use iPads, that would still find value in compatibility with Office file formats. However, a writer for Business Insider argues , better now than later. “In the not too distant future, though, we expect Microsoft to offer Office for the iPad. Microsoft is a software company, and so it should be making the best possible software for the iPad. Otherwise, Google and Apple are just going to do it, leaving Microsoft further behind.”