wVersion

wVersion is a field in the WSADATA structure of the Windows Sockets API (Winsock). It represents the version of the Windows Sockets specification that has been loaded by the Winsock implementation during initialization. The value is a 16-bit word, typically encoded with major and minor version numbers, and can be inspected using macros that extract the low and high bytes (for example, LOBYTE and HIBYTE) or via the MAKEWORD helper.

In practice, a program initializes Winsock by calling WSAStartup, passing a version desired by the application (commonly MAKEWORD(2, 2) for Winsock 2.2). On return, wVersion contains the version actually loaded, while wHighVersion indicates the highest version supported by the implementation. A common compatibility check is to verify that the loaded version matches the requested version (for instance, 2.2), or to compare the major and minor components using the appropriate byte extraction macros.

The 0x0202 value corresponds to version 2.2, which is the standard reference for Winsock 2. In some cases, applications may use wHighVersion to determine if newer features are available, or to fall back if only an earlier version is supported. This field is primarily relevant to Winsock 2 and its compatibility considerations; it is not used in Winsock 1.1 contexts.

See also: Winsock, WSAStartup, WSADATA, MAKEWORD, WSAGetLastError.