Okay so I actually figured this problem out for once but now somehow my Word Processor has made it where it is doing this stupid crap again and I can't seem to figure it out again. Here's what's happening.

When I type it's just fine but if say I notice a typo a paragraph up that I missed and I go back to fix it by deleting something and type a letter then the letter I type replaces the letter in front of it. Example: I spell "that" "tht" and go up to fix it, I type "a" between the "h" and "t" and the "a" replaces the "t" so the word is now spelled "tha" rather then "that". If say the word "cat" is after "that" and I type the "t" to finish off "that" then the "t" will eat the space so now there is no space and I have "thatcat" and so on and so forth.

How do I remove this feature? As someone writing a book it is about 10 seconds away from driving me crazy!

Edit: Sorry if my explanation is slightly confusing with all the "

Press the Insert key. You probably pressed it by accident which set overtype mode. In overtype mode what you type replaces the current character.

Omg thank you!!