When you&#x27;ve got a system that is, for example, underpinning your whole business operation (eg billing, machine controls, whatever) and that cost thousands (often tens or hundreds of thousands) to implement and it only works on a legacy version of an operating system (be that Win 3.11, Linux 2.4, or even just XP) you WILL move heaven and earth to avoid disrupting that system.<p>Even if it&#x27;s a smooth migration to a current release, it doesn&#x27;t have 15 years of perfect history behind it.<p>And that&#x27;s when you can migrate. There are plenty of control systems for devices that cost $millions that were bought decades ago that just need to keep working. You don&#x27;t have source. The vendor went out of business with the dot-com bubble.<p>Yeah, we probably could replace all the things, but at what cost? Will it beat the last 15 years of perfect uptime? Are you the buy willing to stake your job on it? Or shall we just paper over the cracks and keep shovelling coal into that server in the corner?<p>Edit: I&#x27;m describing worst-case scenarios in specific use-cases but even if there isn&#x27;t a good reason to stay behind, the feeling of &quot;why fix what ain&#x27;t broke?&quot; is pervasive in management, especially IT management. Maybe it&#x27;s a generational thing and we&#x27;ll see waves on waves of upgrades in the next decade or two but I&#x27;m fairly sure that&#x27;ll just lead to another generation of &quot;make do&quot;ers.