if you have a problem with an Hitachi HD, you just have to:
- submit a enquiry on their website, using the drive's serial (it'll tell you how long is the remaining guarantee instantly)
- download their test software, and use it
- note the error code
- carefully box the HD and send it
- wait 2-3 weeks for the replacement to arrive
Last time I exchanged a drive through the retailer, it was a 6 (SIX) weeks wait, because they had to test it, report the incident to their central provider, send it; have the incident confirmed, the drive re-tested, the submit operation with the manufacturer repeated, the drive sent yet again (notice how we've lost 1-2 weeks already), then exchanged (another 3 weeks), sent back to the central, then dispatched again, then the client (myself) contacted to get it. Results: 5-6 weeks.
I'd rather contact the manufacturer directly now: it's faster and cleaner.