Microsoft will announce its fiscal 2010 earnings Thursday afternoon, and the pressure is on Redmond to deliver big numbers now that PCs sales have jumped this year, Windows 7 is the "fastest selling OS ever" and Office 2010 is generally available.The elephant in the room will be Apple's $15.7 billion revenues for Q3 2010 that blew past Wall Street estimates. This was a new quarterly revenue record for Jobs and company.Tomorrow's earnings report will mark the end of Microsoft's 2010 fiscal year (which ended June 30). In preparation for how Microsoft's earnings will break down and what the brain trust in Redmond will focus on (and what it will try to conceal), analyst Matt Rosoff from independent research firm Directions on Microsoft outlined seven key themes to bear in mind regarding the state of Microsoft's business.If the Money Makers Are Slipping, Trouble LurksMicrosoft's cash cows are, and always have been, the Windows division, the business division (which includes Office, Exchange and SharePoint) and the Server and Tools division (Windows Server, SQL Server etc). Windows and Office are the most profitable, with around 70 percent profit margins. If all these divisions are growing and profiting then Microsoft is in good health, writes Rosoff. If they are contracting in any way, that means trouble.Other Segments Exist for Competitive Reasons, Not RevenueMicrosoft's Entertainment and Devices division, comprised of Xbox and mobile platforms, provides decent revenue \u2014 about 13 percent of Microsofts total last year \u2014 but very thin margins. The Online segment, mostly advertising from Bing and MSN, accounts for only about 5 percent of Microsofts revenue and has been bleeding money for the last few years. It will probably lose about $2 billion in fiscal year 2010. [ For complete coverage on Microsoft's new Windows 7 operating system -- including hands-on reviews, video tutorials and advice on enterprise rollouts -- see CIO.com's Windows 7 Bible. ]Do not focus on the finances of these segments, writes Rosoff, because they basically exist for competitive and strategic reasons, not revenue. Bing exists to curb Google's revenue growth, which would prevent Google from cutting into Microsoft's Office profits via Google Apps; Xbox gives Microsoft a consumer brand to compete with Sony and Apple; and the mobile business exists to stop competing smartphone platforms from cutting into sales of Windows on portable PCs. Unearned Revenue Shows if Big Customers are Buying"Unearned revenue" offers a good clue about Microsoft's financial health. Whenever enterprise customers like large companies and government agencies make annual payments on multi-year software licensing contracts, Microsoft doesn't book the revenue right away. It puts that money in a bucket called unearned revenue, and then staggers that money into earned (regular) revenue over the course of the year. Fluctuations in unearned revenue indicate how many customers are renewing these multi-year contracts, and how much software they're buying through them. The Latest Windows Is Always the 'Fastest Selling Ever'Windows may be the best version of Windows for many reasons, but is it really the fastest-selling version ever, as Microsoft has proudly touted? No, says Rosoff. \nSlideshow: Windows 7 Hardware in Pictures: The Latest and Greatest Laptops\nSlideshow: Microsoft's Home of the Future: A Visual Tour\nSlideshow: Fighting the Dark Side: Tech's Heroes and Villains\n\n"Windows ships on more than 90 percent of new computers," he writes. "As long as this share remains stable and the overall number of PCs sold keeps growing, then each version of Windows will sell faster than its predecessor."The Magic of Windows SegmentationWhy are there so many damn versions of Windows? Well, Microsoft can't grow Windows revenue by growing market share \u2014 it already has more than 90 percent market share, writes Rosoff. But by dividing Windows into multiple versions, and then trying to get customers to buy a higher-priced version than they did last time Microsoft hopes to boost Windows revenues faster than PC growth. \nGrowth Doesn't Equal PopularityMicrosoft often uses earnings calls to dole out shiny, happy news about particular products without revealing any real information about their sales. For example, writes Rosoff, Microsoft might say that sales of a server product grew 20 percent from last year without mentioning a baseline figure. \n"These statistics might show that a product is flying off the shelves this year ... or it might simply mean that last year's sales were anemic," he says, adding that it's impossible to know how popular a product is unless Microsoft offers specific unit sales or revenue figures.Revenue Doesn't Always Equal DeploymentMicrosoft has recently been boasting that it now has 11 businesses that earn more than $1 billion in revenue per year. But this statistic isn't all that meaningful, writes Rosoff. Often times revenue is granted to SharePoint Server even when it is part of a bundle called the Core CAL that customers buy just to use Windows Server and Exchange Server, and also because the bundle is cheaper than buying the licenses separately. But Microsoft will count these Core CAL packages as SharePoint sales even though customers bought the package for other products.This same type of bundling has been used to push licenses for products like Communications Server, System Center and Forefront security products, notes Rosoff.Shane O'Neill is a senior writer at CIO.com. Follow him on Twitter at twitter.com\/smoneill. Follow everything from CIO.com on Twitter at twitter.com\/CIOonline.