Bluetooth query

Version of Windows?

What Dell Wireless (WiFi) card do you have?  The Dell Wireless 1703 and  Dell Wireless 1704 cards, either of which may have come standard with your 470, both support Bluetooth.  

Go to the support page for this model, select your version of Windows and then select your WiFi card and update the driver.

www.dell.com/.../drivers

If you're not sure which card you have, click System Configuration on that page, enter your Service Tag and review the original configuration (assuming you haven't replaced the original WiFi card).

A Realtek RTL8188CU Wireless 802.11n USB2 LAN Network dongle is plugged in. But I don't think this is for Bluetooth - just a wireless to router connection. There's also a Realtek GBE familly controller built in, but I think that's just for an ethernet LAN.

The Realtek RTL8188CU Wireless 802.11n USB2 LAN Network dongle  doesn't support BT so why are you using it? And why do you even want it since you have an add-in WiFi card in this PC?

Did you use your Service Tag to look at the System Configuration for your PC? That should tell you which specific WiFi card you have so you can update the drivers. Either WiFi card that Dell offered in this model will support BT, but you need the right driver.

And you never mentioned the version of Windows, but you should check to see if BT is turned on in Windows.

EDITED

Did you check your System Configuration on Dell's Support page to see if a WiFi+BT card was installed at the factory?  That's the only way to know for certain what you have, regardless of what somebody else has in their V470. BTW: The specs in the V470 owner's manual doesn't say WiFi+BT is "optional".  

downloads.dell.com/.../vostro-470_owner's manual_en-us.pdf

Do you see WiFi in Device Manager, when your USB dongle isn't connected? If you do, then chances are you have a card that supports BT because either WiFi card that Dell used for the 470 supports BT. But if the driver isn't installed, the card probably won't show up in Device Manager.

And if you updated from the version of Windows that Dell installed to Win 10, you'd need to update the driver.  Note: I see a Win 8.1 and Win 10 driver for Dell's 1703 WiFi+BT card but only a Win 7 driver for Dell's 1704 WiFi+BT card on the support page, either of which was used for the V470.

If you don't have an internal WiFi card, you could get a USB>WiFi+BT dongle to replace the USB>WiFi dongle you have now.   Lots of choices available...

You've misunderstood. My Vostro only came with  Ethernet only which was fine if I wanted to use cables to my router. The dongle was purely an extra to allow me to connect wirelessly to the Internet which I now use in preference.

The reason I raised the BT question is that I'm considering buying some BT headphones. When I read the spec for the Vostro 470 it stated (in CNET I think) that it supported BT. But there's nothing to suggest in Device Manager that there's any hardware included that does support it. I was hoping if anyone out there who's familiar with this particular Dell PC can confirm.

I use Windows 7 Pro and BT is turned on in Services.

Well, I've always assumed Device Manager in Windows is a pretty accurate guide as to what hardware one does have. If there are drivers missing for any hardware you usually see a question mark by 'unknown device'. Not the case here.

The card installed in the PCIe is definitely an ethernet one. It has an ethernet connector which proves it. If I remove the USB dongle there is no Wi-Fi. Only ethernet is then available. Also in Control Panel there is no icon shown separately for BT. And under Devices and Printers, there is nothing hinting at BT either.

So I have to assume that the specs indicate/mean that BT is supported by the Vostro mobo, but as appears to be the case it is not integrated, so either I have to buy another dongle for BT, or live without. Whereas I had originally assumed from the wording of the spec that the Vostro came integrated with BT, The specs are misleading.

The onboard (integrated) Ethernet is not a PCI-e card. Its circuitry is on the motherboard and is not removable the way a PCI-e card is removable. If the onboard NIC fails, you would have to replace the entire motherboard.

On the other hand, a Dell WLAN (WiFi+BT) card is a removable card that would be plugged into the 52-pin PCI-e mini-card slot on the motherboard and held in place with 2 screws.  The antenna cables for the card are behind the bezel on front of the PC.

So if you don't have a card in that mini-card slot, you have 2 alternatives, get a WiFi+BT mini-card or get a WiFi+BT dongle.

Either way, make sure whatever you buy supports the version of Windows that's running.