Microsoft Word drives me up the wall, as do many other fine Microsoft products.
I would die a happy man if I could spend five minutes alone with whatever moron first hatched the idea, "Hey, let's have our software predict what the user wants to do and make changes without asking permission! Then let's make it really, really hard to make any changes from what we think the document should look like!" Seriously, five minutes. Just me, him and a sock full of nickels. Good times.
I'm trying to be calm and even generous, but I think it's honest truth that in all my time working on computers at least 90% of these "helpful" mandatory changes have not only been things I did not want, but things I actively hated and had to spend time fixing. I leave spelling autocorrect out of that equation, but even that isn't anywhere near helpful enough to make up for the rest. Just gimme the green or red line and let me fix it myself. The red and green lines are awesome, to give credit where it's due.
I can't even fiddle with the automatic settings for the program - assuming I can find them - because most of this annoyance comes at work, on computers I share with everyone else, and I can't make sweeping changes like that.
You know what would help? If every piece of software ever sold had a prominent button, toggle or option labeled "Don't do a single <redacted> thing until I tell you to. I mean it, you stupid <redacted>!" I would pay cash money for that feature. I would rob banks and pistol whip orphans to get the cash money to pay for that feature. And then I would shoot the idiot programmer who decided "Let's have that option turn itself off, because no one really wants it anyway."