John O'L -

One of the main places people find the Validation Tool is when they sign up for updates. You normally sign up to allow Microsoft to download and install updates automatically as they become available.

Microsoft doesn't call your machine when updates are available, and the privacy policies with the services discussed in this thread assert that they won't call you to get info about you. Your machine has to "call home" to tell them it's available to be updated, so a scheduler on your machine attempts to contact Microsoft on a regular schedule to see if there are new updates.

I believe the normal schedule is once per week, but if your machine is turned off, or your internet connection isn't available at the regular time, it may attempt an out-of-schedule contact "at the first opportunity," so it could try to make the contact at less regular times.

A recent newsletter noted that Microsoft was updating 300,000,000+ machines monthly. That's quite a bit of traffic, so "retries" may not be too uncommon, which could mean you might see more than the minimum scheduled attempts.

Most people find it convenient to give their firewall permission to allow the contact with the update server "whenever" so that they don't see the notices everytime a contact with the update site is attempted.

You probably do want the Critical Updates, so you need to permit the contacts in order to get them.

John