How to make a notebooks Bluetooth device visible to others? Pairing ?

I have activated the built-in Bluettooth device on a Win7 notebook.

However I cannot pair from some SmartPhones to it.
This was only possible from one Smartphone.

When I scan the Bluetooth devices from other Android smarphones the Notebook Bluetooth is not visible.

I guess I have to make it visible (again) in addition.

But how do I tell Win7 to make it visible?
Where do I get the visiblity time?

Peter

It often depends on what software your using with it but turn it off then turn it on and see if you can see it most only stay visable for a short time for security

Are the Smart phones that don't work on your network? Go to Control Panel, Network and Sharing Center, View Computers and Devices to check this. If not, can you add those phones using Add a Wireless Device.