Many laptop users have machines that support Bluetooth for devices. We have several laptop and tablet machines and most have Bluetooth support.
When Windows 10 was delivered to Windows 7 machines with working Bluetooth, users quickly discovered that it stopped working. We did a clean install on several machines and discovered that the Bluetooth hardware device was not even present at all.
Downloading the device driver from the respective OEM was flagged as incompatible with Windows 10. So here we see Microsoft has changed the driver model and broke backwards compatibility.
We have seen this issue with Bluetooth 2 and Bluetooth 3 based machines. The only solution is to endure a USB port loss and install one of the Bluetooth 4 dongles sold at stores and online. Bluetooth 4 has some advantages but the OEM device should be backwards compatible. For backpack users, a rounded USB dongle left in the port is much less likely to be caught on fabric or cause a tear.
We updated the BIOS on one Lenovo X220 machine and Windows 10 was able to recognize the Bluetooth device. Some devices would pair and some were not successful. We suggest updating the BIOS where available on principle as they can provide many improvements over the initial release.
This is a real headache for those who had Window 10 shoved onto machines. This really hurts Bluetooth vendors who fine disgruntled users galore. Sadly most Bluetooth mice do not come with a dongle for desktop machines or older laptops.