Hiya,its an acer aspire 4810t laptop.the f3 button has a bluetooth icon on it,but still unsure how to turn on.thanks

SOURCE: Acer Aspire 5310 Bluetooth Heeelppppp

I Also have the Aspire 5310 and when you press the bluetooth launch button it says 'No Bluetooth Device', this is becasuse it does not have the Bluetooth card installed into this computer and this is an extra for your laptop... hope this helped.
Thanks

SOURCE: bluetooth location on acer laptop

Bluetooth other than the device itself is software, the "bluetooth dongle" gets plugged into a port via the usb, So I am thinking you need to plug it in to the computer. If it is a new machine if may be internal, that would be under programs, start programs, if no bluetooth it must be installed the software and hardware, good luck

SOURCE: acer aspire 5500z driver bluetooth

First of all check if your Laptop has the bluetooth feature. If it has then the driver should have been automatically installed. There is a button in your laptop, make sure that the bluetooth is on.

Thanks

SOURCE: How do I enable my bluetooth on my Acer Aspire

Make sure you have the driver for the bluetooth installed http://support.acer.com/us/en/drivers_download.aspx
here is a link to the driver downlod page. You can check it by going into System Properties then click on Hardware tab to see if it is installed properly. (right click on My Computer Icon and select Properties to get to the System Properties)

SOURCE: my acer aspire 4810t says no bootable device

enter BIOS - you will see a mesage when you first turn on laptop tellign you to press a key to enter setup. Do this and make sure HDD is listed. if it is, you might have todo a recovery.

Turn on laptop, then immediatly press ALT + F10 keep finger on ALT and press F10 a few times, this will start the recovery process. some ask if you want to re-install windows or full factory reset. Windows install will only repair it - full factory reset will delete any data you have! so be careful