I think it's more of a will this update cripple our 20yr old in house developed app that is crucial for the business that either we don't know how to maintain or lost the source no longer working on the latest windows.
Previous employer, we were on WinXP and compiling a/ VS2003. Upgrade to Win7 mostly effectively crippled VS2003 for reasons I don't know. This necessitated porting our very large (100s of Millions of LOC in C++ to at least VS2008) set of in-house libraries. It should on paper be trivial, but it was a firm wide effort that spanned 18 months. Why? Because someone sent the CEO an xlsx that he couldn't open. This was circa 2007-2008. We were forced to upgrade OS and compiler for the new Office version, but it trickled into a firm wide rebuild of all C++ code. Wasnt pretty or fun.
That would likely turn the 18 month upgrade effort into a 36 month upgrade effort that happens 5 years later.
Sometimes long upgrade cycles are great, but I suspect a yearly upgrade to the latest Visual Studio would have been a lot less painful. Fixing a few small issues is much easier than fixing many of them, and having to do it yearly both makes everyone better at doing it and better at avoiding the creation of such issues.
Previous employer, we were on WinXP and compiling a/ VS2003. Upgrade to Win7 mostly effectively crippled VS2003 for reasons I don't know. This necessitated porting our very large (100s of Millions of LOC in C++ to at least VS2008) set of in-house libraries. It should on paper be trivial, but it was a firm wide effort that spanned 18 months. Why? Because someone sent the CEO an xlsx that he couldn't open. This was circa 2007-2008. We were forced to upgrade OS and compiler for the new Office version, but it trickled into a firm wide rebuild of all C++ code. Wasnt pretty or fun.