Cause: This generally occurs when one tries to view a non-formatted, non-partitioned drive in Windows, or when you try to view a different file type in an OS that does not support that particular file type. For example, trying to view an NTFS partition in Windows 98 will result in this error.
Solution: First use a bootable floppy or CD-ROM, and then use FDISK to see what type of partitions are present on the drive. The fourth option in FDISK lets you do that. If a non-Windows partition exists, delete it and create a new FAT32 or NTFS partition that Windows can recognise. If the drive is brand new, then creating new partitions and subsequently formatting them should help.