Well, that depends. You'd save us a lot of time and trouble if you told us domething about the equipment first.
What kind of Hi-Fi is it, and what types of input/output jacks does it have? Is your computer a desktop or laptop? Does it have a sound card? Does it have a blue Line-IN jack? If it only has a microphone jack, is your computer capable of using the microphone jack as a Line-IN (not all of them are - read your computer manual)?
Thanks Procyon, I have a component Hi Fi and all connections at the rear are used except for video. There is a headphone socket on the front of my amplifier. I'm running a laptop with a sound card but does not appear to have a Blue line in jack. I have USB connections, a microphone jack and headphone jack. I have a Compaq Presario but cannot find any information on whether or not I can use the microphone jack as the Line-In
Then, you need to go into the 'Sounds' category of your Windows Control Panel (assuming you're using Windows - you didn't say) and under the 'Recording' tab see if there's a setting to change the microphone jack into a Line-IN jack.
I understand that the jacks on the back of your stereo are full. That's not what I asked. I need to know the names of the output jacks you do have. You will NOT be using a headphone jack.