There’s one thing I really hate when using Microsoft Word. It’s when I accidentally hit the Insert key and turn on Overtype. Then instead of editing my text, I’m typing over it.
Fortunately, Word allows you to turn off the Overtype function. Here’s how to do it. Start by clicking on File.

Then select Options from the very bottom of the panel that opens as the left.

The Options window will open.

Look for Advanced in the left panel.

Under Editing options, scroll down to Use the Insert key to control overtype mode. Untick the box next to it. You can also untick the box next to Use overtype mode.

Make sure to click on OK to save your change. Then it shouldn’t trouble you again.
Too bad Microsoft doesn’t allow us to use this feature in our Gmails! I have hit that INS key more times than I could ever count and not for the intention it was put there for! It’s SO aggravating to be typing away, not realizing you were losing faster than you were gaining. And just what IS the intention for that key anyway? If I want to insert anything, I can just place my cursor in that spot and type what I wanted inserted.