No direct "one-size-fits-all" download link exists because each VAIO model has a different driver version. Never use driver updater tools that claim a universal Assist button driver—they are often malware.
If you upgraded your VAIO to Windows 10 or 11 from Windows 7 or 8, the original drivers often break. Sony released a specific "VAIO Care" package for newer operating systems.
The Download Link: 👉 VAIO Care for Windows 10/11 (Microsoft Store) (Note: This link works if the Microsoft Store app is active on your PC). sony vaio assist button driver download link
Alternative Fix for Win 10/11: If the button still does not work after installing the app above, you need to force-install the drivers in "Compatibility Mode."
Sony has largely transitioned its support to the Sony Japan servers, and finding the correct file can be confusing. If you upgraded your VAIO to Windows 10
Microsoft hosts many Sony drivers via Windows Update. You can manually download them:
Important update: Sony sold its VAIO business in 2014. The official Sony support website (esupport.sony.com) no longer hosts drivers for most legacy VAIO models. However, you can still find official driver packages on: Sony has largely transitioned its support to the
Sony’s old driver pages were archived. You can search for your specific model at:
https://web.archive.org/web/*/https://esupport.sony.com/