Hello,
What laptop do you have?
You could adjust the audio by using an equalizer to alter the frequencies of the sound (for example, playing music in Winamp and adjusting the EQ in Winamp).
However, while you can use an EQ to improve the audible quality of the audio, amplifying the frequencies, either individually or all frequencies using the 'Preamp' function in Winamp's Equalizer, can cause distortion as EricB said (particularly if it's not optimally configured).