From what I've been able to discover this affects a number of Nokia models. I found this on the nokia support forum from user Mikeyalltrade.
This is quite a simple fix. First you need to open OVI suite on your computer. Do not connect your N8 using a usb cable, just select connect another device. When prompted select "use Bluetooth"
as the option. This will then load all of the required drivers onto you computer extracting them from the OVI suite. You can then sync using Bluetooth or simply close your OVI suite and use Bluetooth as normal on your pc laptop etc.
Also, these threads may help shed some light on your problem >> http://discussions.nokia.com/t5/PC-and-Mac-Software/Bluetooth-driver-Windows-7-64-bit/td-p/702933http://discussions.nokia.com/t5/Connectivity/Supported-Bluetooth-Drivers-Sticky/td-p/1308
Both of which seem to suggest you need the latest nokia suite software. Available here >> http://www.nokia.com/global/support/product/nokia-suite/