Ghost75 Error: Cannot Open Image File

I am trying to create an image of my indows xp system partition using Ghost75 to a FAT32 partition. From the command line I enter

ghost75 -z9 -auto -split=660

I get all the way to “Proceed with partition dump?” and choose OK, but it gives me the error message “Cannot open image file”

Arrghh. This seems like a problem with the path or target directory I wish to use. I have some experience with this program; we use it at work.

Can someone give me some pointers? The system partition is NTFS.

James