In article , lid says...

I purchased a BT 4.0 mouse that can also be used az a USB wireless
mouse, using a 2.4Ghz USB dongle. It works fine on my Win10 Lenovo
laptop in either mode, but on my older HP Win7 PC the BT connection does
not work. I wonder if it is because my HP laptop does not "understand"
the BT 4.0 standard or what? Could it be because the BT 4.0 mouse is not
downward compatible with possibly an older BT standard used by my Win7 PC?

Does your laptop have built-in Bluetooth? Do you see anything to do with
Bluetooth under Device Manager? Is there a Bluetooth icon under Network
and Sharing Center/Change Adapter Settings? My laptops all require a
small add-on USB dongle but obviously newer laptops might have it built-
in.