golang tcp套接字在不同操作系统上的不同行为

I want to simulate the http server with tcp socket written in Go. The program runs well on Linux or Mac, but has some problems on Windows. I have configured the built-in firewall to allow connections on the port. On Windows, when the browser requests the program, it shows me "This site can’t be reached. The connection was reset." Instead, it can response "Hello world" correctly on Linux or Mac. As follows.

// implement http server with tcp socket
package main

import (
    "log"
    "net"
    "os"
)

var content = []byte(`HTTP/1.1 200 OK
Content-type: text/plain

Hello world!`)

func handleConn(conn net.Conn) {
    conn.Write(content)
    defer conn.Close()
}

func main() {
    addr := "localhost:10000"
    listener, err := net.Listen("tcp", addr)
    checkErr(err)
    defer listener.Close()

    for {
        conn, err := listener.Accept()
        if err != nil {
            log.Fatal(err)
            continue
        }
        go handleConn(conn)
    }
}

func checkErr(err error) {
    if err != nil {
        log.Fatal(err)
        os.Exit(1)
    }
}

I try to change some code to read all the bytes from the connection on Windows, after that, the program responses correctly.

func handleConn(conn net.Conn) {
    var buf = make([]byte, 1024)
    _, err := conn.Read(buf)
    checkErr(err)
    conn.Write(content)
    defer conn.Close()
}

But I don't know why must I read all the bytes of connection on Windows.