I found the original stickied topic for this issue:
"In order to use the sound programs associated with the Mastering Astral Projection daily exercises, you'll need to install the BrainWave Generator shareware program on your computer. 30 days after installing the shareware a message comes up asking you to register the software. The message remains there for several seconds. Eventually, the message disappears and you can use the software normally.You never need to register your software. It will always work for free."
-Brian Mercer