Problem with external disks

do you know its item name eg, /dev/sda

sorry but i am quite new in linux systems.
the name of the disk is /media/external.
the disk contains mp3s and its NTFS formating.
before i download the new release everything was ok.

Can you tell us the output of a sudo fdisk -l command?

Can you also tell us the output of an ls -l /media command?

when i excecute the ls-l command:

Disk /dev/hda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot Start End Blocks Id System
/dev/hda1 * 1 5665 45504081 7 HPFS/NTFS
/dev/hda2 5666 9560 31286587+ 83 Linux
/dev/hda3 9561 9729 1357492+ 5 Extended
/dev/hda5 9561 9729 1357461 82 Linux swap / Solaris

Disk /dev/hdb: 81.9 GB, 81964302336 bytes
255 heads, 63 sectors/track, 9964 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot Start End Blocks Id System
/dev/hdb1 1 9964 80035798+ 7 HPFS/NTFS

Disk /dev/sda: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot Start End Blocks Id System
/dev/sda1 1 20203 162280566 7 HPFS/NTFS
/dev/sda2 20204 30401 81915435 f W95 Ext'd (LBA)
/dev/sda5 20204 20214 88326 7 HPFS/NTFS
/dev/sda6 30401 30401 8001 7 HPFS/NTFS

and when i excecute the sudo -l :

σύνολο 46
lrwxrwxrwx 1 root root 6 2007-05-12 21:36 cdrom -> cdrom0
dr-xr-xr-x 1 root root 2048 2007-04-17 17:43 cdrom0
drwxr-xr-x 2 root root 4096 2007-05-12 21:36 cdrom1
drwxr-xr-x 2 root root 4096 2007-05-12 18:55 External
lrwxrwxrwx 1 root root 7 2007-05-12 21:36 floppy -> floppy0
drwxr-xr-x 2 root root 4096 2007-05-12 21:36 floppy0
drwxrwxrwx 1 root root 16384 2007-05-19 23:20 hda1
drwxrwxrwx 1 root root 8192 2007-05-18 02:02 hdb1
drwxr-xr-x 2 root root 4096 2007-05-12 18:55 palaios
drwxr-xr-x 2 root root 4096 2007-05-12 18:55 PALAIOS

OK, try to do this in this order and tell us the results:

1) ls -l /media/External
2) mount -t ntfs /dev/sda1 /media/External
3) ls -l /media/External

Also please give use the content of the /etc/fstab file.

sorry for not answer earlier but i 've been away from my pc for this time...

so
1) ls: /media/External: No such file or directory

2)mount: mount point /media/External does not exist

3)same as #1 except if i am logged in like flyefta when its says "total 0"

4) fstab file contains:

 /etc/fstab: static file system information.
#
# -- This file has been automaticly generated by ntfs-config --
#
# <file system> <mount point> <type> <options> <dump> <pass>

proc /proc proc defaults 0 0
# Entry for /dev/hda2 :
UUID=1ddc89c3-868f-43e8-a7fb-96db94013708 / ext3 nouser,defaults,errors=remount-ro,atime,auto,rw,dev,exec,suid 0 1
# Entry for /dev/hda1 :
UUID=A62C6F6E2C6F3887 /media/hda1 ntfs-3g defaults,locale=el_GR.UTF-8 0 1
# Entry for /dev/hdb1 :
UUID=3C3844E438449F30 /media/hdb1 ntfs-3g defaults,locale=el_GR.UTF-8 0 1
# Entry for /dev/hda5 :
UUID=180a2728-7a5b-4282-9846-1e5b2e4a366d none swap sw 0 0
/dev/cdrom /media/cdrom0 udf,iso9660 user,atime,noauto,rw,dev,exec,suid 0 0
/dev/hdd /media/cdrom1 udf,iso9660 user,atime,noauto,rw,dev,exec,suid 0 0
/dev/ /media/floppy0 auto user,atime,noauto,rw,dev,exec,suid 0 0
LABEL=palaios /media/External auto nouser,atime,noauto,rw,nodev,noexec,nosuid 0 0
/dev/sda2 /media/External auto nouser,atime,noauto,rw,nodev,noexec,nosuid 0 0
LABEL=palaios /media/palaios auto nouser,atime,noauto,rw,nodev,noexec,nosuid 0 0
/dev/hdb1 <σημείο\040προσάρτησης> auto nouser,atime,noauto,rw,nodev,noexec,nosuid 0 0
LABEL=External /media/external auto nouser,noauto,atime,auto,rw,nodev,noexec,nosuid 0 0

Thanks Cesare Tirabassi, that solved my question.