Click the "
Latest Software" link at the top of the page for the software to load music on the player. It's called "emplode" and you'll want the "2.00final" version of it. You'll also need the "2.00 developer version" of the player software. It is the most stable and up-to-date. Both emplode and the player software need to be the same version.
For the "hard disk not found" message, you may want to spend a little time reading the FAQ. It is probably the best FAQ I've come across on the internets. But, since you're in a pinch, the entry you're looking for is
here.
Finally, since you've found Tony's Logo Editor (assuming that's what you used to change the boot logo), I suggest using its Kernal Flash utility (built in) to install the latest
Hijack Kernal.