---
title: "W7100A-S2E Firmware"
url: "https://maker.wiznet.io/forum/10547"
markdown_url: "https://maker.wiznet.io/forum/10547/md"
type: "Forum topic"
category: "MCU & Boards"
author: "gbit"
created: "2014-09-25T07:45:54+09:00"
last_activity: "2017-05-04T08:39:59+09:00"
language: "en"
views: 1094
replies: 3
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W7100A-S2E Firmware

## Question

Asked by gbit on 2014-09-25 in MCU & Boards.

Hi,
we have bought this chip with the firmware v. 3.14 preloaded.
Do we have to update at the version 4.03?

I have seen that this version is for WIZ107SR with HW ver 1.4, I use the W7100A-S2E on my custom hardware.

Best Regards,
gbit

## Replies

### Reply 1 by jameskim, 2014-09-25

Hello,

You can use FW 4.03 on your W7100A-S2E.
If you can search W7100A-S2E with WIZnet’s Configuration tool, then you can upload a new firmware onto W7100A-S2E.

Thank you.

### Reply 2 by shabbir, 2016-02-02

Hi,

I am using W7100-S2E with wiz107sr Firmware in my Design. ver 4.04.
Board working fine but suddenly i see that MAC address reset to FFFFFFFF… .
how can i recover the MAC? is any way i can re write the MAC ID?

Regards
shabbir

### Reply 3 by jameskim, 2017-03-20

Hello,

Please refer to the below link to rewrite MAC address on your module.
[url][Problem with Wiz107SR: not found by configuration tool after firmware upgrade](https://forum.wiznet.io/t/problem-with-wiz107sr-not-found-by-configuration-tool-after-firmware-upgrade/2252/1)]

And to avoid this issue happens again, please update your module with the latest firmware, V4.06 after writing MAC address again.

Thank you.
BR,

James.

---

Source: https://maker.wiznet.io/forum/10547