i have a lacie 160 gb external hard drive(it's just a drive no operating system)which i use only for mp3's on my computer at home which is ran on windows xp, but how do i run, operate and listen to those mp3's on linux systems?

what _kind_ of external drive?
Firewire? Usb? SCSI? ATAoE?

most hardware in linux are emulated as SCSI, plug it on and check to your log ( type dmesg ) to see to which device to system assigned it. Then you will need to mount it.

it's usb 2.0

ok, so USB is emulated as SCSI
plug it in and type "dmesg". You should see some line about a "new drive being found". Note the device name (probably "sda").
If you know what partition is on it, you can mount it right then (mount /dev/sdaX /mnt/my_happy_thingy as example, where X is the partition number). Or you can use fdisk or cfdisk to take a look to partition ( example : cfdisk /dev/sda ).

i'm sorry i don't understand about plug in and type, type it where, i know nothing about linux systems

1-Plug your drive into your USB port on your computer
2-Open a console (text mode, terminal, konsole, whatever your GUI use, that thing that look like DOS mode)
3- Type "dmesg". You will have a lot of text scrolling by. Only the last few line are important, something that should look like : 4-This tell you the name of the device, in my case, "sda". Note that your lines will be different, of course. To mount something you need 2 things. The name of the device AND the partition number. We already have the name.
5- Type "su - " to login as root in the text mode.
6- Type "cfdisk /dev/THE_DEVICE_YOU_FOUND" (change this line according to your device name)
7- Now you should have a listing of your hard drive partition in front of you. Take note and leave cfdisk
8- We have name and partition number... We can attempt a mount. Syntax of mount command is like "mount /dev/DEVICE_NAMEPARTITION_NUMBER /where/you/want/it". So create yourself a folder (the way you prefer, if you want to use textmode, type "mkdir /folder/you_want_to/create/" )
9- Mount your drive to the folder. In my case, I mount my drive to /mnt/other1 and I only have 1 partition so my mount command is : "mount /dev/sda1 /mnt/other1" but you could (will have to) change it to fit your system
10- Now you should be able to use the drive. Note it may be read-only for normal user, if you made it there, I'll tell you how to change this

it says this device is not regognized by any installed usb driver

can I see the message? paste me the 10-15 last lines.

it won't save

To copy & paste in linux
- Highlight the text with the left mouse button then click with your middle mouse button (or click the scroll wheel or click left & right simultaneously) on the place you want to paste.

So highlight in the konsole and paste in the text box in your web-browser.

Daniel