You can access your PC network share folders using the built-in File Explorer. Tap Menu-->Open Path-->New Path... and type your desktop computer name. It will request credentials. Input your desktop username and password.
!!!Helpful hint!!!
Desktop Windows machines contain by default "administrative shares", hidden shares that you can't normally see. They exist for programming functionality and for network administrative full access to remote machines.
If you know the Administrator account password, you can connect with full administrative permissions to any drive on your desktop even if no shares are created on the desktop. In the New Path... input field, enter
\\computername\c$ to access the root of your desktop C: drive. D$ for D: etc.
This also works for desktop-to-desktop networking.