A folder under PCs was disappeared

I used to have a folder under PCs on the menu bar on the left side of the screen. I recently bought a new notebook computer and try to make connection to this folder. After I entered a microsoft account code, I couldn't get an access to this folder. I can't remember what I clicked on, but there was a dialog box asking about disconnection. After I clicked it, the folder was gone. Is there any way I can get back to this folder under PCs? Thank you for any helps.