I'm the user who solved the first question in comments.
First, I want to make it clear that I wasn't sure at all that changing os.system to os.startfile would work in their case (the question isn't exactly a MCVE, with tkinter wall of code all over, which also explains the lack of answers then, or even comment upvotes), else I would have closed that as a duplicate.
Those system calls / windows questions are sometimes hard to answer without being able to reproduce the issue with the exact context. That was a "have you tried ?" comment. Nowadays I tend to try to avoid answering in comments.
Then I suggested the OP to edit their question because it was 1) solved and 2) trivial. Since noone had answered and the question was already "old" (several minutes is old for a python question), no harm done (and no risk of question ban evasion, this question wasn't downvoted)
Of course, that wouldn't have been the same if someone had already answered (and OP commenting/accepting the answer), but in that case, I think I would have closed that as duplicate instead of having one good faith answerer "chameleoned" by OP.
That said, I think that question needs more trimming. There's still too much useless code that makes the question unclear.
(and sometimes SO works in mysterious ways, so I don't claim to know it a lot more than you)