Line in jack not plugged in

I am trying to record from a cassette player on to my hp envy h8-1500z. I have a cable going from the headphone jack on the player to the blue line in jack on the pc. I have gone to the recording devices and have the line in jack enabled. That is as far as I can get because it says it is not plugged in? I have plugged it into the mic jack and it recognized that. I have tryed updating the drivers to no avail. I would appreciate any insight. I did the recommended fixes. Registry repair etc.

somewhat solved

I never figured out why the jack doesn't work. I bought an Ez-Cap for $20. Which has a rca and headphone cable to usb interface with audacity software. Works great.