Tcl_DStringInit(&ds);
    if (GetComputerNameExW(ComputerNamePhysicalDnsFullyQualified, wbuf, &length) != 0) {
	/*
	 * Convert string from native to UTF then change to lowercase.
	 */

	Tcl_UtfToLower(Tcl_WCharToUtfDString(wbuf, TCL_INDEX_NONE, &ds));

    } else {
	if (TclpHasSockets(NULL) == TCL_OK) {
	    /*
	     * The buffer size of 256 is recommended by the MSDN page that
	     * documents gethostname() as being always adequate.
	     */

	    Tcl_DString inDs;

	    Tcl_DStringInit(&inDs);
	    Tcl_DStringSetLength(&inDs, 256);
	    if (gethostname(Tcl_DStringValue(&inDs),
		    Tcl_DStringLength(&inDs)) == 0) {
		Tcl_ExternalToUtfDStringEx(NULL, Tcl_DStringValue(&inDs), TCL_INDEX_NONE,
			TCL_ENCODING_NOCOMPLAIN, &ds);
	    }
	    Tcl_DStringFree(&inDs);
	}
    }

    *encodingPtr = Tcl_GetEncoding(NULL, "utf-8");