I have got a Notebook Acer V3-571G-53216G75Makk after upgrading BIOS with "Acer Aspire V3 series BIOS mods - better Nvidia GT 640m performance" my bluetooth adapter has vanished out of my system. After i had uninstalled all drivers for Wlan and bluetooth, the driver for Bluetooth informs that the controller for bluetooth hasn't been installed. After downgrading BIOS to standard version that has been downloaded from the official site acer.com, BT-adapter hasn't appeared again. My drivers for Bluetooth controller : BT_Broadcom_6.5.1.2410_W7x64 Could you help me please?