As someone who moved over to Word from Word Perfect many years ago, I can sympathize with the pain of changing word processors. The transition was ugly, but I wasn't alone. Over the years, many people have migrated from Word Perfect to Word. In response to the large number of new users, Microsoft added a couple of options designed to help these new users get acquainted with the World of Word.
Unfortunately, these options have caused more trouble than they are worth. If the Word Perfect options are turned on, weirdness results. For example, new Word users may wonder why when they select a block of text and press the Delete key, nothing happens. Delete should mean delete, after all.
However, if you check the status bar at the bottom of the screen, you'll notice that it says, "Delete Block? No (Yes)." The idea is that if you press Y to confirm the delete, the text goes away, just like the old days of Word Perfect. But most people when they press the Delete key have already made the command decision to delete text now, so the extra step is overkill.
To make Word behave better, you need to remove the option settings that relate to Word Perfect. Choose Tools|Options and click the General tab. You'll notice two options at the bottom of the list regarding Word Perfect. Remove the checkmark from both check boxes and click OK. You will be rewarded with an absence of delete confirmation messages.