iPod Classic won't go into diognostic or disk mode

I've been having trouble with my 160gb iPod classic the last few days, after deciding to sync it for the first time in 5 years. It keeps coming up with different error problems half way through syncing or causing my iTunes to freeze and eventually I have to restore the iPod. Restored it about 5 times in the last 2 days. However, this time an error message came up saying it couldnt be restored due to an unknown error. I had it in disk mode at the time so rebooted it but it froze on the apple logo. I thought I would try putting it in diognostic mode for the first time to see if that could give me any clues as to what was wrong. However it doesn't seem to want to go into diognostic mode and is now refusing to go into disk mode too.
After sitting on the apple logo for a while it came up with a picture of the iPod end of the usb wire, saing 'Connect to itunes to restore'. So I've plugged it into my laptop (Windows Vista) but it isn's showing up in iTunes...just making my iTunes freeze.
Anyone got any ideas? Unfortunately I haven't got the money to buy a new iPod so I really need this one to be fixed. Unfortunately technology seems to hate me (My laptop stopped working so having to use my mums...my external harddrive giving up ghost after only a couple of years for no reason what so ever, my iPhone not working properly etc etc etc)

I miss the days when you could just plug in an MP3 player and copy the files onto it like you do a memory card *sigh*