I’d like to let you know that, beginning at the end of this month and continuing over the next few months, we’ll be rolling out an infrastructure update to the Windows Update agent (client).  I wanted to take this opportunity to provide some background on the update and discuss the value these updates bring to you.

How Windows Update Keeps Itself Up-to-Date

Occasionally, we must update the infrastructure of Windows Update in order to ensure a high level of service quality, reliability, and operation. As part of this process, we update both the back-end infrastructure that supports the service as well as the client side code (i.e. the Windows Update agent, or client).

So what are we doing this time? Well, this particular update won’t really change the way the client looks or feels to you, but you may notice some improvements in the length of time it takes Windows Update to scan for updates and how quickly you’ll receive signature updates. For example, in this update, we’ve invested heavily in reducing the amount of time it takes the Windows Update agent to scan to see if new updates are available. In this case, we’ve seen some instances of the scan times on some machines decreasing almost 20 percent.

Source- Microsoft update Team Blog