One of the things that makes Microsoft Office a great suite of products is the integration between them.
Which is what makes dealing with Outlook attachments so frustrating. Let's say you get an email in outlook with a word doc attached. If you open that document from the email, edit it, then click save, and close it, do you know what happens? It gives no prompts, takes your save, and then moves on.
But the next time you open that attached word document, it does not show your "saved changes" so where did they go? What happened?
Well, the changes do get saved. to a temp folder. This post on groovypost.com shows how to find where they are. But the fact that you can open and edit files attached to emails with no warning that changes are not applied is ridiculous. This has been an issue for years, and I'm amazed that Microsoft has not addressed it...
open regedit, and find the following entry based on what version of office you run:
it will show you where the temp files are stored/saved.