Hello,
With the Windows 11 update from April 2026 (KB5083769), Microsoft has significantly tightened the requirements for driver signatures (WHQL). This specifically means: drivers without a current Microsoft certification will no longer be loaded.
Affected:
- HEX-USB+CAN
- HEX-USB
- KEY-USB
- Micro-CAN
These interfaces were produced between 2004 and 2016 and use the FTDI chip with a modified driver that was never WHQL-certified. The driver is technically over 20 years old and has not been offered by Ross-Tech for almost 10 years. Ross-Tech has confirmed that there will be no WHQL certification for these legacy drivers:
https://forums.ross-tech.com/index.php?threads/54948/
This is not a bug in Windows 11 - VCDS switched to Windows' own HID drivers with the HEX-NET (in 2014), and these drivers work perfectly fine with Windows 11.
Workarounds:
1. Disable Memory Integrity (Settings → Update & Security → Windows Security → Device Security → Core Isolation).
Force driver signature verification via Shift+Restart → F7 (disables for the current session only).
3. Use an old PC with Windows 10.
All of these workarounds are insecure, not permanent, and will be overwritten by Windows with each update.
Recommended: Upgrade to HEX-V2 or HEX-NET
Both current interfaces use the standard HID drivers from Windows, so they do not require separate drivers and are therefore 100% compatible with Windows 11. In addition, they support vehicles from the 2019 model year onwards, the new SFD-Online function (beta), and HEX-NET also supports DoIP.
Our upgrade program: You can upgrade your old interface to our latest, unlimited system at a discounted price.
https://shop.dieselschrauber.org/en/vcds-interface-upgrade-p-342.php
For hobbyists, there is also the option to purchase a current interface.
https://shop.dieselschrauber.org/en/vcds-diagnosesoftware-von-ross-tech-c-23.php
Best regards, Rainer.