SoundMAX is motherboard audio, nothing to do with USB audio.
Also please see Important information for Windows XP users about the security risks of running XP now that Microsoft do not support it.
Another issue may be that a new HP laptop would not come with Windows XP. Have you installed XP over the Windows 7 or 8 that comes with the laptop? Is this what you are trying to adjust - http://wiki.audacityteam.org/wiki/Mixer_Toolbar_Issues#xpcp?
If you have 64-bit Windows XP your mixer does not support that.
Are you selecting the correct recording device in Audacity’s Device Toolbar?
Gale