---
title: "Accidentally uploaded WIZISP firmware instead of ConfigTool"
url: "https://maker.wiznet.io/forum/14490"
markdown_url: "https://maker.wiznet.io/forum/14490/md"
type: "Forum topic"
category: "Serial-to-Ethernet & ConfigTool"
author: "pnn16004"
created: "2022-03-02T10:16:14+09:00"
last_activity: "2022-03-08T04:34:17+09:00"
language: "en"
views: 456
replies: 1
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# Accidentally uploaded WIZISP firmware instead of ConfigTool

## Question

Asked by pnn16004 on 2022-03-02 in Serial-to-Ethernet & ConfigTool.

With the S2E Configuration Tool I uploaded the wrong firmware to the small version of [WIZ750SR](https://eu.mouser.com/ProductDetail/WIZnet/WIZ750SR-232?qs=W0yvOO0ixfHHFypYuz%2F5OA%3D%3D).

Now the ethernet is not connecting like it did before, and there is no USB input so I can reflash it easily.
What are my options?

## Replies

### Reply 1 by rena, 2022-03-08

Hi [@pnn16004](https://maker.wiznet.io/u/pnn16004) ,

You can recover WIZ750SR firmware using ISP Tool.
In this case, you should use the entire firmware file. (Boot+App)

To use Boot mode(ISP mode), please refer to the following link (‘3. Does it work in ISP mode’ part)

- [\[WIZ750SR\] I can not firmware upload (ISP mode)](https://forum.wiznet.io/t/topic/4309)

Guide to recover WIZ750SR:

- [Flash Programming using WIZISP Tool​](https://docs.wiznet.io/Product/S2E-Module/WIZ750SR/developers_guide-EN#flash-programming-using-wizisp-tool)

---

Source: https://maker.wiznet.io/forum/14490