To the best of my knowledge, iTunes does not have a dark mode.
Regarding the two links you provided:
- the writing style of the first article you link to is (for the sake of diplomacy) - interesting. Not only that, but in an article specifically about dark mode in iTunes for Windows, it wanders off topic and talks about dark mode on a Mac, as well as about other features of iTunes that have nothing to do with dark mode. If the people who wrote that also wrote instructions for getting to the moon and back, I would not be confident of ever seeing planet earth again and I certainly wouldn't be travelling with them. More to the point, the suggestion they outline is the setting for dark mode in Windows, not iTunes
- your second link is about dark mode for Windows, not for iTunes. I do wonder if the people who wrote your first link have mi-read this article
To the best of my knowledge, there has never been a dark mode in iTunes for Windows.
Was there once this option and it was removed? If not why are there so many articles telling you how to do it?
For the same reasons that there is so much mis-information about lots of things. One of those reasons is that Apple have no control about other people write on other websites about iTunes.
while I am at it was is the reason or possible benefit for removing my Apple sourced version of Itunes and removing lots of files and then installing a Microsoft App store version?
Apple didn't do it, perhaps you made the choice without realising, although I have no idea how. The supposed benefit of the Microsoft App Store version is that it updates automatically, whereas the version from Apple relies on the user specifically selecting to update.
Now - the advantages of the using the Apple sourced version include:
- that should an update be broken, you have a chance to avoid it, by not updating
- you can be confident that iTunes cannot simply update when you're in the middle of something. I'm not saying that the Microsoft sourced version does, but since Windows 10 can - and does, update when you're in the middle of something important, why would anyone have confidence in the version of iTunes from Microsoft? (Note to Apple, even though they probably won't see this: read that again and take on board what I have said)
- it doesn't appear to suffer the issues that the Microsoft Store version does
The advantages of using the Microsoft app store version are: