Back in September of 2007 Microsoft pushed a stealth update for the Windows Update mechanism. According to Microsoft, there’s another update to the Windows Update mechanism ready to be unleashed. The difference between this update and the stealth update from back in 2007 is that Microsoft is being more open about this update and actually talking about it before it hits the download servers and starts getting installed on systems.
Here’s the reason given by Microsoft:
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.