Path Field Limits
These constants define the maximum length for the path and for the individual fields within the path.
Maximum length of directory component
Maximum length of drive component
Maximum length of extension component
Maximum length of filename component
Maximum length of full path
The C Runtime supports path lengths up to 32768 characters in length, but it is up to the operating system, specifically the file system, to support these longer paths. The sum of the fields should not exceed _MAX_PATH for full backwards compatibility with FAT32 file systems. Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003, Windows Server 2003, and Windows Vista NTFS file system supports paths up to 32768 characters in length, but only when using the Unicode APIs. When using long path names, prefix the path with the characters \\?\ and use the Unicode versions of the C Runtime functions.