Win32 Resource File

This document details the structure of the resource binary file (.RES) format for Win32 platforms (W95 and WNT). The structure is very similar to the existing Win16 (W3/W3.1/3.11) structure, but it supports some new data types and data structures. One important enhancement is the DWORD/WORD alignment of structures/fields which increases performance of new 32 bit microprocessors but makes resource reading/writing a bit more complex (structures are of dynamic size). The order of the fields of resource data structures is not changed due to alignment, but some padding is required between fields.

The Win32 resource file contains one or more binary resources merged in a single file and aligned on DWORD boundaries. Each resource has its own header structure followed by resource data. Immediately after the resource data comes the header for the next resource followed by resource data, and so on.