By Brian Livingston
A raging controversy over whether Windows patches ever reboot a PC without permission has been solved. Reboots can happen when you’re not expecting it — but you can minimize the problem or eliminate it entirely.
This subject sparked a debate when reader Evan Katz wrote in to ask whether Microsoft patches had started rebooting Windows automatically, even when the Automatic Updates control panel is configured to notify the user of downloads instead of installing them without notice. His comments were printed in the paid version of our Dec. 15, 2005, newsletter.
I’ve found that there are several little-known cases in which a Microsoft patch can trigger a reboot when you’re not expecting it. No, my findings don’t support a conspiracy theory — Microsoft hasn’t deliberately changed its patches to make you lose your unsaved work in surprise reboots. The true answer lies within the secrets of Windows.
How patches can automatically reboot
In my research, I interviewed Mike Cook, a security support engineer in Microsoft’s Product Support Services (PSS) team. We turned up several reasons why a PC that requires a reboot might do so without warning:
1. Settings in the Automatic Updates control panel. The default for Automatic Updates is "Automatically download recommended updates for my computer and install them every day at 03:00," or whatever time is specified. If this option is selected, patches will be downloaded from the Microsoft site in the background and installed automatically at the specified time, after a 5-minute countdown is displayed. Re-installing Windows or some Windows components can silently reset Automatic Updates, making reboots happen without user intervention.
2. “Helpful” security add-ons. Some Microsoft programs can reset Automatic Updates to its most automatic option. The beta of Microsoft’s Windows OneCare Live security program, for example, notifies the user upon installation that this will be done, but this can easily be overlooked.