Razer device is not detected in Razer Synapse 3 after a Windows 11 update

Updated: 08-Feb-2026 | Answer ID: 20498
This article provides instructions to resolve an undetected Razer device in Razer Synapse 3 after a Windows 11 update.

Effective February 3, 2026, Razer Synapse 3 will no longer receive updates or support cloud services. After this date, cloud syncing of configurations across PCs using the same Razer ID will be disabled.

Note: Your installed devices will continue to be configurable in Razer Synapse 3. However, if you uninstall these devices completely, you will need to upgrade to Razer Synapse 4 to continue customization.

Download Razer Synapse 4 and migrate your existing Razer Synapse 3 profiles using the Profile Migration Tool to retain access to your configurations. See How to migrate your Razer Synapse 3 Profile to Razer Synapse 4 for instructions.

Windows 11 updates (KB5066835 / KB5065789) may affect how Razer Synapse 3 communicates with your devices, causing them to not be detected. Follow the steps below to check if these updates are installed.

  1. Press the Windows key + I to open Settings.
  2. Go to “Windows Update” > “Update History”.
  3. Check the list for Windows 11 updates KB5066835 or KB5065789.

If these updates are installed, follow the steps below to help Razer Synapse 3 detect your devices.

  1. Uninstall KB5066835 / KB5065789 (with proper precautions).

    1. Go to Settings > Windows Update > Update History.
    2. Click “Uninstall Updates”.
    3. Find KB5066835 or KB5065789 and uninstall them.
    4. Restart your PC.

  2. Disable HTTP/2 support so that connections revert to HTTP/1.1.

    Note: This involves editing the Windows Registry. Back up your registry first and proceed only if you are comfortable.

    1. Press Windows + R to open the Run dialog.
    2. Type “regedit” in the box and press “Enter”.
    3. Change these two entries:
      • EnableHttp2Tls = 0
      • EnableHttp2Cleartext = 0
    4. Restart your PC.

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