Factbox: Microsoft's patchy deal history

Microsoft Corp has agreed to buy Nokia's handset business for $7.2 billion, but there is no guarantee that acquiring the fading cellphone pioneer will accelerate the PC-centric software company's lumbering move toward mobile computing.

Over the past two decades Microsoft has spent billions of dollars buying or investing in scores of companies as a shortcut to obtain the technology or market presence it does not possess. But few of those deals have yielded great results.

Dell - Microsoft agreed to lend $2 billion to Michael Dell and private equity firm Silver Lake to help finance their move to take PC maker Dell Inc private earlier this year, but the deal has been held up by shareholder opposition, even as Dell's fortunes decline.

Yammer - Paid $1.1 billion last year for online social network business Yammer, but has said very little about it since and does not break out its financials.

Nook - Last year Microsoft agreed to invest $605 million in Barnes & Noble Inc's money-losing Nook e-reader and college textbook business over five years. The bookseller said in June it would stop making the Nook as sales fell 20 percent, badly trailing Amazon.com Inc's market-leading Kindle.

Skype - In May 2011, the company signed a deal to buy online video chat company Skype for $8.5 billion, a price that was considered high at the time by analysts. Microsoft says consumer demand is rising and Skype revenue increased last quarter, but stopped giving user numbers this year and does not divulge the actual financials of the service.

Yahoo - After offering to buy the former internet company in 2008 for $47 billion and being rebuffed, Microsoft signed a 10-year deal to provide internet search services to Yahoo Inc in exchange for a cut of the ad revenue. The deal has disappointed both companies so far.

Danger - Reportedly paid $500 million for the edgy smartphone designer in 2008, but most staff left and two years later Microsoft launched the disastrous Kin phone based on a Danger blueprint. The Kin was supposed to appeal to the under-30 Facebook generation, but was pulled off the market in less than two months after poor sales.

Facebook - Scored a home run with a $240 million purchase of a 1.6 percent stake in the social network in 2007, which is now worth much more and paved the way for co-operation between Facebook Inc and Microsoft's Outlook email and Bing search engine.

aQuantive - paid $6.3 billion in cash for the online ad company in 2007 and wrote off virtually all of that in 2012, effectively admitting the investment had been worthless.

Great Plains/Navision - the acquisition of these two companies in 2001 and 2002, respectively, laid the foundation of Microsoft's corporate software business and is considered a success.

Bungie - Paid only tens of millions of dollars for game studio Bungie, creator of the mega-hit shooter game Halo, in 2000. Bungie eventually split from the company, but Microsoft kept the lucrative Halo franchise.

AT&T - In 1999, Microsoft bought $5 billion in stock of cable and telephone company AT&T Inc with the aim of getting its Windows software into set-top boxes, but it did not deliver the desired entry into the emerging cable-based broadband market.

Apple - Invested $150 million in a struggling Apple Inc in 1997 and committed to make software for the still unpopular Mac. The deal ended a long-running patent spat between the two companies but arguably saved Apple and put it on course to eventually eclipse Microsoft financially.

(Reporting by Bill Rigby; Editing by Phil Berlowitz and Andre Grenon)