Windows 7’s native Bluetooth stack conflicts with Sony’s. Uninstall the Bluetooth device in Device Manager, then install Broadcom Bluetooth drivers v6.5.1.2600 before rebooting.
If possible, install VAIO Care or the VAIO Event Service . These enable special functions like the "Assist" button and FN key shortcuts. Common Troubleshooting Drivers Sony Vaio Pcg 31311X Windows 7
Knowing your internal components is key to finding compatible drivers if the official Sony support page is unavailable. AMD Dual-Core E-450 or E-350. Graphics: Integrated AMD Radeon HD 6320 or 6310. Audio: Intel High Definition Audio. Windows 7’s native Bluetooth stack conflicts with Sony’s
The PCG 31311X typically includes Intel or AMD processors, a specific wireless card (often Intel or Atheros), and a Realtek audio chip. Windows 7, unlike Windows 10, does automatically fetch most drivers via Windows Update. You must supply them manually. These enable special functions like the "Assist" button