14. Microsoft Windows 10 "Nagware" Upgrade Efforts Rile Customers, Partners

Windows 10 launched in July 2015 to generally good reviews, no doubt a relief to the software giant following the criticism the product's predecessor, Windows 8, received following its debut.

But the initial applause for Windows 10 turned to boos from some partners and consumers earlier this year as Microsoft's efforts to convince users to upgrade to the new OS became increasingly aggressive – some even calling the efforts abrasive and heavy-handed.

Partners complained about annoying Windows 10 upgrade pop-up windows and "nagware" buried in security patches. When Microsoft re-classified the upgrade from optional to "recommended," some users awoke to find that their PCs had upgraded to Windows 10 without their knowledge. Some customers even called Microsoft's efforts outright deceptive when on-screen messages recommending the upgrade seemed designed to trick users into accepting Windows 10.

Some Microsoft partners were already unhappy with the software giant over the company's decision last year – with little notice to the channel – to offer Windows 10 as a free upgrade for a year.