File Saving With A Random Capital Letter. How Do I fix It?

So I have a file that I've tried renaming, saving by replacing, and I've even copied each page over and resaved everything in a new file to save as the same name to try to remove this one capital letter that just bugs me.

Heres a Screen Shot:

You can see it doesnt effect the back up file at all. And with this one I save in a different folder and then moved to the main folder I use for this file and it reverted to having the "P". I think when I originally created the file I had a Capital P and it just never wants to forget my mistake, lol. 

I know this is more of a windows thing but Whats happening here?