Problem Formatting New WD Drive

[Kashchei]

I just bought my wife a new WDElements external drive and try as I might, I can't get it formatted. On the box it says that it is compatible with Windows and OS X 10.5.3+ and she is running Leopard, so I don't think this is the problem. The drive came formatted in MS-DOS (FAT), and when I try to reformat it to Mac OS Extended (Case-sensitive, Journaled) I get the attached error message. Can anyone help me get past this normally tiny hurdle?

 

[BlueRevolution]

Hmm... what happens if you manually unmount the drive prior to formatting?

 

[Kashchei]

The drive mounted on my wife's machine before I tried to reformat it to Mac OS Extended. Once I tried to do that, I got the error message I posted and ever since then I have been unable to mount the drive on her machine or any other. I hope this helps someone to solve this problem because I'm at my wit's end!

 

[rpaloalto]

Is it a Intel mac?
Try going into disk utility. Select partition and choose GUID partition under the options tab.
It must be partitioned as GUID first.
Then erase an reformat as Mac OS Extended (journaled)

 

[Cave Man]

Make sure you're initializing the drive in Disk Utility, and not the DOS partition that is below and indented under the drive name. Is there a reason why you need case-sensitive initialization? If not, you probably shouldn't. When you click on the drive a new tab called "Partition" should appear. Click on that and under the Options tab make sure it's set for GUID if you're on an Intel Mac, or APT for a PowerPC Mac.

 

[Kashchei]

Make sure you're initializing the drive in Disk Utility, and not the DOS partition that is below and indented under the drive name. Is there a reason why you need case-sensitive initialization? If not, you probably shouldn't. When you click on the drive a new tab called "Partition" should appear. Click on that and under the Options tab make sure it's set for GUID if you're on an Intel Mac, or APT for a PowerPC Mac.

Viele Danke, RPaloAlto & CaveMan! I had no idea I needed to partition as GUID, but now, thanks to your help, all is working well. Thank you so much for your help! Happy New Year and Prosit Neujahr!