In other words, it performs a very similar role to what Windows 7 Service Pack 2 would have done, if only Windows 7 Service Pack 2 were to exist. Installing the rollup will perform five years of patching in one shot. The company has published a 'convenience rollup' for Windows 7 Service Pack 1 (and Windows Server 2008 R2), which in a single package contains all the updates, both security and non-security, released since the Service Pack, up through April 2016. The answer to that particular question will, unfortunately, remain a mystery, but Microsoft did today announce a change that will greatly reduce the pain of this process. Typically, this means multiple trips to Windows Update and multiple reboots in order to get the system fully up-to-date, and it is a process that is at best tedious, typically leading one to wonder why, at the very least, it cannot pull down all the updates at once and apply them with just a single reboot. Service Pack 1 for the operating system was released in 2011, meaning that a fresh install has five years of individual patches to download and install.

Anyone who's installed Windows 7 any time in the last, oh, five years or so probably didn't enjoy the experience very much.