Recording a mix on my hp laptop with a DJM 450 mixer ?? tried rekordbox and audacity

@Ashley > The DJM-450 uses ASIO drivers, which Audacity does not support "out-of-the-box." You would need to compile a version which does support the proper drivers, but the instructions to do that are far too complex for the average user.

You can use rekordbox to record (even in Export mode); simply configure the recording input within the rekordbox preferences to match the recording output from the mixer.