I would like to request a modification of a closed faq thread
http://www.misticriver.net/showthread.php?t=33996
I find this way easier, using a freeware program to sort files and winamp to make the playlist.
Step 1: Sorting all files into directories by the first letter can be done much faster and more easily by using a free file called filesieve2. Search for filesieve2.zip and you should find it. Then point filesieve at your PMP's audio directory (e:\audio\ for me) and tell it to output to the same directory, click next and click next again. It will run in about 2 minutes for my 1100 songs but I didn't do any of the work.
Step 2. Open winamp and clear any songs from its playlist. Then add directory and add e:\audio including subdirectories this will add all the songs in the new subdirectories.
Step 3. Have winamp save the playlist right onto e:\audio as "songs.m3u".
Step 4. Disconnect the USB cord, power the PMP up, go to music, go to the audio folder, go the the songs.m3u (go up instead of down so you don't have to pass the whole alphabet), hold the select button, load the playlist, switch to the playlist using the b button and press play. If you have your player set to shuffle, it will randomly play songs on the playlist regardless of what folder they are in.