Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a portable hard drive that has been formatted as NTFS with all the default values in Windows xp, the drive shows up on my Windows XP computer but doesn't show on my Windows Seven laptop. It's enclosed in a Western Digital Passport case, and when I attach it to the USB port it does make that New Hardware found chime.

The hard drive itself originates from the same laptop which has windows seven installed on it. I upgraded my laptop to the Western Digital drive but now I cant access the old drive on my Windows Seven PC as an external, it does however work on my Windows XP netbook.

What do I do?

Thank you so much!

For people who have important data on the drive, I would recommend this solution, though my hard drive was empty so I went with this more simple answer.

share|improve this question
up vote 1 down vote accepted

Try this:

  • Right-click on the computer icon on your desktop Select Manage
  • When the Computer Management tool opens, double-click "Storage" then "Disk Management". You may see your drive there but it has not been assigned a drive letter.
  • Right-click on the drive and select change drive letter.

This has happened to me in the past, I'm not really sure why it happens.

share|improve this answer
Oh thanks! "this drive is offline because it has a signature collision with another disk that is online" makes sense, gonna google it and see what to do : ) – Mohammad Aug 6 '10 at 14:42
Dan I've updated the question with the answer. – Mohammad Aug 6 '10 at 14:50

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.