Regex - File Path - Drive letter and UNC paths

\A
(?:[a-z]:|\\\\[a-z0-9_.$\●-]+\\[a-z0-9_.$\●-]+)\\   # Drive
(?:[^\\/:*?"<>|\r\n]+\\)*                           # Folder
[^\\/:*?"<>|\r\n]*                                  # File
\Z

NOTE: Free-spacing, case insensitive.

^(?:[a-z]:|\\\\[a-z0-9_.$●-]+\\[a-z0-9_.$●-]+)\\(?:[^\\/:*?"<>|\r\n]+\\)*[^\\/:*?"<>|\r\n]*$

NOTE: Case insensitive.