Corporate IT problem solving after a Windows update
In the old days, MS used to release a dozen individual patches each month. I despatched the updates to test devices -- test environments and to real users trying to get their jobs done. Some patches -- e.g. anything related to .NET framework -- were tested intensively. If something broke, I had to determine whether it was patch related or other change related. And with all of that testing, I still discovered problems on live PCs months later.
With the switch to two release bundles, testing (or the identification of a problem update) becomes easier; the security bundle or the improvement bundle broke something, or something else did it. My problem solving is also easier -- I won't release the bundle that broke things. Until I work things out.
Unfortunately, I have agreements with customers that I will provide them with Windows updates. I have signed contracts with financial trade bodies promising that my PCs fit their regulations. If I can't install an old fashioned individual fix, I can expect perseverance on their part. If I can't install a bundle -- and a later bundle won't install as a consequence -- I'm heading for trouble.
My software suppliers promise fixes if I have a problem; one of my suppliers is Microsoft and one of their hotfixes took 18 months with no guarantee that the fix changes would survive other security patches.