Does the Acer Aspire 5520 have bluetooth?
I have an Acer Aspire 4520 (which is just a screen size smaller) so this should work. There should be a button above the keyboard or on the front edge of the pc with the bluetooth symbol on it. Press it and if it starts flashing that means the bluetooth is turned on. If it says “no device” on the screen when you press it, it means there is no bluetooth on your pc.