How to format an external hard drive that is not visible in management

[Tonyhvd]

I am unable to see my new USB portable WD250G HD. Worked OK originally and carried two partitions, second one for Fedora. Something went wrong during the Fedora upgrade and now the drive is no longer visible.
Shows up OK on my MAc and I can format it in NTFS with MBR, but still not visible in XP.

 

[house70]

If you want to format completely the HDD, you can use a low-level format tool, like killdisk. After that, you can re-format the HDD to your liking. if you need details how to do that, let me know.