Requirements
Client: Included in Windows XP, Windows 2000 Professional.
Server: Included in Windows Server 2003, Windows 2000 Server.
Unicode: Implemented as Unicode and ANSI versions.
Header: Declared in Sddl.h.
Library: Use Advapi32.lib.
ConvertSidToStringSid
The ConvertSidToStringSid function converts a security identifier (SID) to a string format suitable for display, storage, or transmission.
To convert the string-format SID back to a valid, functional SID, call the ConvertStringSidToSid function.