I tried a lot of way to do this, and I always come back to the current solution. Net version will give the possibility to re-assign multiple CD and/or DVD. But I need more informations about what is returned by DISKPART; so could you run DISKPART and give the output of the command LIST VOL (especially what is displayed for your CD-R, CD-RW, DVD,...)? What I would like to have is someting like: Volume ### Ltr Nom Fs Type Taille Statut Info ---------- --- ------- ------ ---------- ---------- --------- -------- Volume 0 E DVD-ROM 0 B (Comment: CD-RW burner, DVD reader) Volume 1 M XPCREATE CDFS DVD-ROM 859 MB (comment: DVD-RW burner) With your answer to my above question, I think I will be able to modify mapdrive so you will be able to set the letters as you want it Note that mapdrive is based only on the DISKPART results (but DISKPART does not see any differences between a DVD-R burner and a DVD-RW burner . I hope it will report different types for CD Reader and CD burner )