One one hand older computers may not run the updates.
On the other hand your antivirus or any combination of security programs you installed, or incompatibility with applications you installed may be preventing the updates.
And if I had a third hand, I would erase all the updates and turn the updates off permanently.
But a lot of people seem to dwell on the importance of these updates and I can't personally see that they are doing a lot of good.
And that is why so many people have decided not to use them, but rather rely on third party security solutions instead. That solution has been working fine for me.