Well, if one simply does not install updates, it gets rather easy, as long as the hardware does not act up.
Which is of course, a really bad idea for the general case.
Although it is actually kind of a requirement in some industrial environments, where certifications are involved - once the thing is certified, any change, hardware or software, requires a re-certification, which apparently is expensive and tedious. Which is how many industrial plants, too, end up running on ancient computers, at least by todays's standards.