Hi,
Not sure that I understand what your issue is.
Being able to monitor the mic / line level input, through the speakers is a function of the soundcard and operating system.
To see if you can get the functionality working, click Start > Control Panel > Sound > Audio Tab > Volume > Options > Properties… Make sure for input that Stereo Mix and Record Control are ticked
If you search the WWW, you’ll find there’s often little chance of getting the monitor function working in Vista, due to certain features of its architecture.
Cheers
M