software shows as if there is no microphone and no entry of line in.
the device-manager (win 7) shows that these devices exist.
I tried with another software and there is the same problem.
please, help me, friends. 
Topic moved to the Windows forum.
Check that the recording input is enabled in the Windows Sounds control panel: http://wiki.audacityteam.org/wiki/Mixer_Toolbar_Issues#vistacp
see this:
It looks like your microphone is not plugged in. Do you have a microphone plugged in?
Youâre right !
I have a problem with the entry. I should hold it while plugging it in.
Thank you steve!
May you help me more (maybe it should be at a special subject) -
How can I get the device of âmixed stereoâ in order to record directly from the pc ?
Alternatively may I make a direct connection between the entry of âline inâ and the exit of the speakers?
It doesnât look like your sound card has that option.
Yes you can. You just need a short (stereo) cable to connect the two together.