I have a Studio 1558 laptop, originally with Windows 7 which I upgraded to Windows 8.1 Pro. I have just installed a larger HD (1TB) to replace the 500GB which I thought might have been on its way out as it occasionally started clicking. I have also taken the opportunity for a clean install of Windows 8.1 Pro. But the Device Manager does not show any Bluetooth devices even though the Bluetooth mouse works! However I cannot find any links in Devices & Printers to allow me to change the mouse wheel action or the Synaptics touch pad action.
Going back to the 500GB HD gives me all this functionality so the hardware is all ok. The BIOS settings still have Bluetooth enabled. I have updated Windows updates, and used Slimdrivers to update all the drivers.
Where do I go from here?
(It may just be a coincidence but I used Windows 8.1 Pro disk as used on my desktop and am waiting for another Windows 8.1 Pro disk with another product key as the one used on my desktop cannot be used twice.)