Hi,
Yep the navigation pane or left column listing can be expanded just by clicking on the small triangle symbols
Once you see a folder you want to see the images click on it and just those images will be displayed,
I personally wouldn't worry about the tweeter.... listings
If you have an account with either of these social networking sites simply use that sites upload features if you want to post an image,
The other part where you describe looking for an image on F drive.. sounds like your using windows explorer and not windows photo gallery to go to where the images are,
That will always open a file/ image in a minimal photo viewer which photo gallery has one of those and it does confuse people because once you want to edit... you can't
It then opens in the full editor photo gallery with All photos and videos selected as you first describe,
This is frustratingly normal behavior unfortunately
I would suggest opening photo gallery then look for the files in it then all of the tool options are already there and available without trying to find the file again in all of the clutter,
But one small trick is when it does open the full editor simply hit the Enter key and see if the file you first opened appears in the editor,
Cheers.