No sound

Hi, I just installed Audacity as I want to finaly copy my old vinyl records on CD
For this I use a Lenco L3866 USB turntable and linked this to my IBM PC.
Installing the Audacity software (with the turntable already switched on and the USB cable in my computer)
I noticed that where the instruction manual tells me to press Micophone and change it into Stereo Mix,
there is no data/words whatsoever in this little box.

However I managed to get things working, I recorded my first vinyl, and exported it to both a .wav and a .mp3
file (using LAME)
And now I have the following problem/error.
If I want to play either one of these files with Windows media player, I hear no sound at all!
Where if I open Audacity, load the file and use Audacity to play, I can hear sound.

Probably an easy/stupid setting issue, but I tried all kind of settings and cound not get it working.
Plse does anyone know how to solve ??

Thanks Muiden

Export as “16 bit 44100Hz Microsoft PCM WAV”

In Audacity 1.3.x you can do this through the Export dialogue - for Audacity 1.2.x, check the on-line manual for details.

This is expected behaviour - when you plug in a USB TT like this Audacity hands over complete control over the sound services to the USB device, so no options are available in the input selector dropdown - the input slider in Audacity is likely to be inoperable too, for the same reason.