Drag & Drop folders method does not create a list of folders with Sansa Express

I am a new user. After reading the manual, I made copies of my folders (artists,albums) into Sansa express. All the folders were there with mp3’s in them after checking with windows explorer. However, the player did not recognize the folders!. It showed me all 228 files(tracks) with the correct file names. I thought I would see all 8 folders and some subfolders. I deleted all folders. I moved all the same folders with Windows media player. It worked perfect. Everything is neatly organized. I can select any folder (artist, album) and listen to it. So, the question is:
Do I have to use WMP to move files into the player if I want neatly organized music list? or did I do something wrong with dragging and dropping?
Second question: How do I change the battery eventually? Do I have to send the player back to Sandisk?
Thank you.

Hi Stepk!  Im bored at work… so heres your answer!

None of the sansa players show the tracks by the folders they are in.  All your music is organized by the ID3 tags… so as long as those are organized the way you want, you will still achieve the same thing

2:  You cannot change the battery.  You can tell this because sandisk does not offer end consumer purchasable battery replacements, like they do with the E200 and C200 players.  You would have to contact them.

Thanks for your reply Bleach. IT WAS MY FAULT. I don’t think any player recognizes folders Windows explorer creates! Here’s my brief story:
I have almost 8000 aac (apple ipod) tunes. I ripped my own CD’s, and use them with ipod. I also own few mp3 players. I found free software that converts music files from Download.com. I created a folder called mp3’s on my desktop. I converted some folders(albums) from aac to mp3. I neatly created foldersand subfolders. When I copied them onto my Sansa Express, My computer showed that all the folders were there. However, after I unplugged the player, it showed everything in numerical and alphabetical order. this free software called Switch does not add tags. Only song names as file names.
Yahoo Jukebox support told me that their software does not convert from aac into mp3. Does WMP do this? I haven’t tried contacted Apple yet. I dont’ want to rip all these cd’s again.
Do I have any choice?

one more question? Does 64 kbps wma file sound as good as 128 kbps mp3 file? if it does, doesn’t it make sense to have wma files since you can move more songs into players?