Your computer might not have a FireWire port and even if it does, it's no use unless you have a FireWire iPod cable. Skip the test or reset your iPod and do manual tests, which in any case will be more informative.
Check your iPod with Diagnostics Mode
It's possible that your iPod's hard drive has started to fail. Take your iPod and place your right thumb on the centre SELECT button and your left on the top MENU button. Press down both thumbs for about 6 seconds until your iPod reboots. Immediately move your left thumb around to the rewind button |<< on the left and hold this down together with SELECT for a further 6 seconds. Your iPod should now switch into Diagnostic Boot mode. Press MENU for Manual Test, then select IO > HardDrive > HDSMARTData to reveal your stats. For comparison here is a sample of mine from 6th Generation Classic after I'd had it for about 2 years.
Pending Sectors: 0
PowerOn Hours: 2202
Temp: Current 24c
Temp: Min 10c
Temp: Max 50c
Take a note of your results. When finished press SELECT & MENU for 6 seconds to reset the iPod again.
With modern disc drives sectors are no longer marked bad by a disc scan, if the SMART firmware detects a sector it has trouble accessing it will attempt to invisibly reallocate it to a spare area of the disc.
Note that I've only 12 remapped sectors and none pending. To help explain what the numbers mean here is an extract from the Wikipedia S.M.A.R.T.article:
Reallocated Sectors Count
Count of reallocated sectors. When the hard drive finds a read/write/verification error, it marks this sector as "reallocated" and transfers data to a special reserved area (spare area). This process is also known as remapping, and "reallocated" sectors are called remaps. This is why, on modern hard disks, "bad blocks" cannot be found while testing the surface – all bad blocks are hidden in reallocated sectors. However, as the number of reallocated sectors increases, the read/write speed tends to decrease. The raw value normally represents a count of the number of bad sectors that have been found and remapped. Thus, the higher the attribute value, the more sectors the drive has had to reallocate.
Number of "unstable" sectors (waiting to be remapped, because of read errors). If an unstable sector is subsequently written or read successfully, this value is decreased and the sector is not remapped. Read errors on a sector will not remap the sector (since it might be readable later); instead, the drive firmware remembers that the sector needs to be remapped, and remaps it the next time it's written.
Large numbers of Reallocs or Pending Sectors would suggest your drive is failing and that you may need to repair or replace your iPod. Check your stats after another attempt to update your iPod. If the numbers increase that again points to hard drive failure. While it won't be good news at least you'll know it isn't some random software problem and you can decide what to do next.
The reallocated sector count is possibly not the most useful statistic as these are sectors that, in principle, have been remapped and now work properly. How many pending sectors do you have? Restoring the device should release these so they can be remapped but it doesn't always happen and if there is an active difficult/impossible to read sector holding important data like part of the iPod's database or a folder then the device won't work properly. You may find it helps to reformat the iPod's drive before using iTunes to restore it.
I performed the diagnostic and here's what I get and it's not what I expected:
Pending Sectors: 0
PowerOn Hours: 6
Temp: Current 26c
Temp: Min 22c
Temp: Max 34c
I've had this Classic since Sept 2007 and I've used it a lot so I'm surprised at the results, to say the least. I've never had any problems with this iPod and it's got over 30,000 songs on it. Any ideas why I get these results? I'm not too worried because of my lack of problems but I'm still curious.
TT2 I ran this on 6th Gen 160gb and found:
Pending Sectors: 128
Power on Hours: 114
Start / Stops: 7392
I cannot get the iPod to sync comes up with error and appears to only load on a handfull of songs and then stops, I'm guessing I'm into replacing the Hard Drive or binning it??
Assuming all your media is in your library, hopefully backed up also, then you could put the device into disk mode, format its hard drive and restore. Don't put any media on it to start with, but confirm that the pending sectors have cleared into reallocated sectors. Then try putting your media back on and see what happens to the stats at the end of the process. If you are lucky you have a limited section of the drive that won't read reliably but the device is still usable once those bad sectors have been mapped out. If the stats gets worse that would suggest more serious damage to the drive, which is unlikely to get better, so you'll have to decide what to do next.
Try Erase your iPod - The Super Fix for most iPod Problems. Basically a low level format of the iPod’s hard drive to get around whatever problems might be stopping iTunes from fully restoring it.
Once you've restored your iPod don't rush to dump all the data back exactly as it was before. I have found that lots of large or complex smart playlists can sometimes trigger constant reboots or dumping of the iPod's library. In addition, larger transfers can fail leaving data in an inconsistent state. Try this technique for populating the iPod in stages.
Break up large transfers
In iTunes select the menu item File... New Smart Playlist. Change the first drop-down box to Playlist, the next to is and the next to Music. Tick against Limit to, type in say10, then change the drop-down to GB, and set the last drop-down to artist. When you click OK you can enter a name for the playlist, e.g. Transfer. Now sync this playlist to your iPod rather than your entire library. When the sync is complete modify the rule (File... Edit playlist) to increase the size by your chosen amount, then sync and repeat. You can experiment with different size increments, if it doesn't work just choose something a bit smaller until it works each time. Before long you should have all your music on your iPod. Once that's done you can move on to other media such as podcasts, videos, photos, playlists etc.