Не знакомился плотно с Zinc 3.0
На Zinc 2.5.0.34 работает такой вариант:

Код:
// подключаем системную DLL kernek32.dll
var kernel32 = new mdm.DLL(mdm.System.Paths.windows + "\\system32\\kernel32.dll");
kernel32.addParameter("string", "G:\\");
var res = kernel32.call("integer", "GetDriveTypeA");
out.text = res;
kernel32.clear();
kernel32.close();
/*Функция GetDriveTypeA возвращает число от 0 до 6
DRIVE_UNKNOWN (0) The drive type cannot be determined.
DRIVE_NO_ROOT_DIR (1)The root path is invalid, for example, no volume is mounted at the path.
DRIVE_REMOVABLE (2)The drive is a type that has removable media, for example, a floppy drive or removable hard disk.
DRIVE_FIXED (3) The drive is a type that cannot be removed, for example, a fixed hard drive.
DRIVE_REMOTE (4)The drive is a remote (network) drive.
DRIVE_CDROM (5)The drive is a CD-ROM drive.
DRIVE_RAMDISK (6)The drive is a RAM disk.*/
В цикле пробежать по всем буквам и узнаете тип каждого диска. Узнать буквы дисков можете так:
http://flasher.ru/forum/showpost.php...95&postcount=5