The bluetooth devices are offline in Windows 8.

I followed this post from another thread and it works:

I chose to upgrade my Sony Viao VPCJ12LPOE  (All-in-one desktop PC) from Windows 7 to Windows 8.  The Windows 8 compatibility checker advised that I should uninstall the Broadcom (Widcomm) Windows 7 Bluetooth drviers as they are incompatible.

After the upgrade to Windows 8 everything else worked fine but I was left with no means of connecting Bluetooth devices to my PC. ( a problem reported elsewhere in these forums.

I have applied the following fix today and all is now working great.  

Bluetooth is an embedded device needing Windows 8 compatible drivers.

To reiterate: I upgraded two days ago and suffered the loss of my Bluetooth after being advised to uninstall the Broadcomm (Widdcomm) driver before upgrading.

Today I installed the Windows 8 compatible Broadcom Bluetooth Driver from the Lenovo web page (see link below) and  I have since successfully added the following blue tooth devices to my PC that is now running Windows 8 (all now connecting):  my IPhone 4s, my IPad 3, my Panasonic music centre with IPod/IPhone dock and my works Lumia 800 Windows Phone.

Copy and paste the link below into your browser and download and install the Broadcom (R) Bluetooth Driver s1blt3us17.exe listed.

You will then see the Bluetooth icon appear in your system tray at the bottom right hand side of you desktop after a restart.  Right click and select 'add a Bluetooth device'.  This will take you to the Windows 8 'Device' page.  Put the device you want to be added into pairing mode and click the + add device button. 

Once added, stay patient and don't go clicking around until windows has installed the device drivers (small blue progress bar will appear under the name of the device).

Once done you will find a new TILE added on the Windows 8 'Start Screen' for each device added.  Click on the tile for the device and the 'Bluetooth Control box will start up and appear on your screen.  From here you will see the device you have just added and you can click on 'connect' (to connect) and 'disconnect' (to disconnect once connected).

http://support.lenovo.com/en_GB/downloads/detail.page?DocID=DS032438&rss=true

I know this works and my instructions here can be fully trusted.

Good luck.  Trevor.