Some problems Windows users experience when installing updates include computer crashes, unexpected restarts, sudden nonfunctionality of devices and software, and driver updates that actually break drivers. For example, a 2014 Windows 7 update resulted in "blue screen of death" errors for many users. In 2009, after a problematic antivirus update, some McAfee customers discovered their computers suddenly couldn't boot up. In 2013, a faulty firmware update plagued Surface Pro 2 users for a month until Microsoft finally addressed the error.
Periodically, Windows Update freezes a system completely. For instance, a 2013 algorithm error permitted the update process to claim 100 percent of system resources, often for multiple hours. The coding mistake rendered the machines useless for the duration.
Following the debut of Windows 8, a handful of critical updates created issues for some laptop users. A necessary update wouldn't install, for example, without rebooting in safe mode and removing audio drivers; it can be an overly technical process for the average user. Two prior updates that similarly impacted laptop computers were unaccompanied by any troubleshooting advice or support from Microsoft whatsoever.
Some users are chagrined by what they perceive as sneakiness on the part of Microsoft's intrusive updates. In early 2015, news broke that Windows Update had been surreptitiously downloading a hefty 6GB file, the Windows 10 upgrade, onto systems running Windows 7 and 8.