Some require drivers, some don't and I do encounter folk that are challenged at setting up not only the adapter but the steps to pair and operate Bluetooth in general. All this is on the web so here I don't write how to install or use but need a little more.
1. What OS?
2. Did you try a few USB ports? Some front ports are just bad.
3. Four models? Which ones?
If I were to try again, I'd pick a best seller from Amazon's list. These are not overly expensive.
I've bought 4 different dongles and none of them work on the Dell T1700. When I use a dongle specific to the device like a mouse and or keyboard it works. What do I have to do to add bluetooth to my Dell T1700 so my Plantronics headset will work. It works on my Acer PC MC605 no problem. I've asked Dell and they said nothing I can do will make the Dell T1700 workstation Bluetooth compatible.