Can't really say for sure what cables you'd need. But in most systems, the tape player would have phono out (one for each channel i.e. left and right) and the soundcard would have a 15mm stereo jack. If you don't have the phono out, then you can use the headphone socket on the tape player (in which case use a stereo jack to stereo jack cable). The phono out is the better option as it will give you a line level output. The headphone socket will be at greater level. Once connected, go to the windows mixer and enable the line in, play the tape and you should hear it through the computer speakers (be careful of the volume if using headphone as your signal). You'll then need some recording software on the computer. This will usually have a meter indicating the level. Play the tape during the louder moments and adjuct the input level so it doesn't reach the red (indicates clipping). Once you're satisfied with the level, start recording. You may need to select bitrate, and sample rate too.