that is not the "default" pictures folder on my computer. How do I make it the one that shows up in the list under "This PC?" Or change the screen saver "Pictures" to the folder in "This PC?"
I'm loath to get involved in anything like this, as it seems to always end with something being lost or disappearing into the ether and then I get scolded for trying to help.
C:\Users\YourUserName is your profile folder and its' child objects (sub-folders and files) should be what you see under "This PC"
IF you are logged in with that User Name / Account
I can only say that.....
IF you have not altered the default "Location" of the "Pictures" folder then the "Pictures" folder under "This PC" should always point to C:\Users\YourUserName\Pictures
IF it does not then maybe.....
FIND out where it is pointing....
First make sure you are looking at the navigation pane on the left side of File Explorer correctly and only under "This PC" and you are not confused by the contents of "Quick Access" or "One Drive", then.....
Right click it and choose properties and under the "General" tab of the properties dialog box look adjacent to the text "Location"
IS it pointing at C:\Users\YourUserName ??
IF not, then (and here's where it gets tricky) you can use the "Location" tab to move it. You need to pay attention if you choose to do this and probably, when prompted, choose to move anything that may be contained in the current pointer / location into the new pointer / location
AND I say "pay attention" and I'll add be careful as this is when people leave abandoned / orphaned locations or end up with a bunch of duplicates that they don't want.
Typically, if you haven't done anything intentionally to move things around, then all the hierarchical tree under "This PC" should point to their proper place in C:\Users\YourUserName\ (all the sub-folders).
IF they're not, then I don't have any explanation except to suspect some type of issue with the profile (User Name) that you are using, and.....
THAT's why I asked "where are they currently pointing to"?