Driver dates

Have you ever noticed that all Windows built-in drivers have the same value in the last update field? Have you wondered why? If you read Windows update logs, it's pretty obvious that Microsoft updates its drivers, so why isn't that date changing?

Well, Microsoft has now explained why this happens, and according to Microsoft software engineer Raymond Chen, this isn't an accident or bug, but intentional behavior, meant to allow users always to use the most appropriate driver.

Only Microsoft drivers show this date

To understand why this happens, you need to know that your computer runs using drivers that come built-in with your Windows OS, and drivers users install on their own, or Windows finds online and installs for users.

According to Chen, the June 21, 2006 date is rewritten only for the first category, of drivers that ship with Windows.

The reason is "driver conflicts," situations when there are multiple drivers to choose from for the same component.

According to Chen, Windows works by selecting drivers by three simple rules:

  1. If a driver matches a component's exact hardware ID, then regardless of source, Windows will choose that driver.
  2. If multiple drivers are installed, Windows selects the driver with the most recent timestamp.
  3. If drivers have the same update date, then Windows selects the driver with the highest version number.

Hidden trick ensures appropriate drivers don't get disabled

While these rules make sense, they can also cause a lot of problems. One such example is when users install custom drivers on top of the one(s) provided by Windows.

Obviously, the custom driver provided by the hardware's vendor is most suited to manage that specific component, something with which even Microsoft agrees.

But problems occur when Windows updates its built-in drivers. When this happens, this results in Microsoft's weaker drivers having a newer update date than the custom drivers, which would mean that a less-specialized driver would end up replacing the custom driver.

June 21, 2006 date has a secret meaning

To avoid situations like these, for the past 11 years, Microsoft has been resetting the last update date for all its built-in drivers to June 21, 2006, which is the day when Microsoft released Windows Vista RTM.

"Since only drivers as far back as Vista are compatible with new versions of Windows, every driver should have a date newer than Vista RTM, preserving the driver you installed as the best ranked driver," another Microsoft employee going by the name Zac also wrote on Reddit.

"It all works out in the end, but it does look a bit funny," Chen also added.