I've just installed RealDrum and got this error when trying to load a real drum: mp4/aiff file doesn't exist in the same folder as txt or in another folder. Any help? All the realdrum got the same error.

You most likely purchased the ProPak or MegaPak. These packages DO NOT include all the audio accessories available for Band-in-a-Box. Each is missing some of the available RealTracks, RealDrums, MidiSuperTracks or midi styles. The first package to include all the audio accessories is the PlusPak.

You can also purchase audio sets that include Realtracks gathered into sets.

Hung Vo,
This may or may not include your issue, but here is a recent thread regarding problems with realdrums loading: http://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=280219#Post280219

Has anyone figured out how to solve this problem. I am getting the same error message. Any help or suggestions would be appreciated.