Bluetooth: cannot locate device, no bt icons in device manager or tray

[Gimel]

Bought a secondhand Acer 4820T laptop win7 Home - 64 bit
It had been restored to factory settings + SP1 installed. All working fine save for bluetooth.

There is a bluetooth service installed, but I don't see anything else.

When I click add a device laptop does not not find anything. Bluetooth keyboard works
fine with a couple other win7 laptops I have.

(The service was set to manual but even started and on automatic no difference)

I don't know what to download to fix this - Acer have four or more bluetooth downloads

I see on this other laptop I'm typing this on, there is a generic bluetooth adapter and enumerator under bluetooth radios in device manager - the acer lacks these.

 

[wither 2]

Does this help-

How to Connect Bluetooth Keyboard to Laptop - YouTube