You can use a HD with the advantech CE/Boards. Although you won't be able to use the MP3 Player from Utopiasoft. This software requires a MIPS or SH3 processor. The advantech boards are X86 based. You would need to have a MP3 player made for X86. Which is exactly what I'm doing. Check out my Topic "New MP3 Player". Also do a search at advantech's web site for "windows ce".