---
sidebar_position: 4
title: Install Let's Encrypt certificates on Windows
description: Fix Let's Encrypt certificate trust issues on Windows that cause HTTP 400/500 connection errors.
---

In some circumstances, you may face an error that reads like `Http response at 400 or 500 level, http status code: 0`.
On Windows machine, this is usually due to [Let's Encrypt](https://letsencrypt.org/) certificate not being trusted.

To fix this, please follow the steps below:

* download this file https://letsencrypt.org/certs/isrgrootx1.der
* open it (double click on the file)

![Certificate window](images/open-certificate.png)
* click on "Install Certificate" and follow the instructions:

![Import certificate](images/certificate-import.png)

Then you should be able to try again.

If it still doesn't work, could you check if it was correctly installed by opening the certmgr (typing "`cert`" in the search box should show it)

![Manage user certificates](images/manage-user-certs.png)

And then it should be under `Trusted Root Certification Authorities\Certificates`:
![Certificates manager](images/certmgr.png)


---

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