Originally Posted by Aussienews

Once a weakness is found in a particular driver or device, that driver will
have its signature revoked by Microsoft, which means that it will cease to
function (details on this are a bit vague here, presumably some minimum
functionality like generic 640x480 VGA support will still be available in
order for the system to boot). This means that a report of a compromise of a
particular driver or device will cause all support for that device worldwide
to be turned off until a fix can be found. Again, details are sketchy, but if
it's a device problem then presumably the device turns into a paperweight once
it's revoked. If it's an older device for which the vendor isn't interested
in rewriting their drivers (and in the fast-moving hardware market most
devices enter "legacy" status within a year of two of their replacement models
becoming available), all devices of that type worldwide become permanently
unusable.