My computer won't let me type in passwords for security-enabled wireless connections.

When ever I click on a full signal security-enabled network to connect to the internet, instead of coming up with the password box, my computer says:

“Windows is unable to connect to the selected network. The network may no longer be in range. Please refresh the list of available networks, and try to connect again.”

I even tried going to the networks properties and typing the password in, but it still didn’t work.
It used to allow me onto many different networks.

Any ideas would help out a lot! Thanks!