Corrupted Partition Table on External USB Data Backup Drive

I have a Western Digital MyBook ES 500 GB external hard drive (USB and eSATA interfaces) for data backups formatted from a Windows XP PC that I now use with my laptop running Windows 7 64-bit Home Premium. Recently my son connected it to his Apple PC and tried to create a partition to back up his files. Apparently this corrupted the partition table. I can no longer access any data on the hard drive. The drive does not appear in Computer but does appear in Device Manager and Disk Management.

I believe the problem is that the partition table (formatted for Windows) was modified by an Apple computer so that Windows can no longer tell what file system is on the partitions. My son is gone for a month and I no longer have access to his Apple computer so I can't plug the drive into an Apple computer to check if the drive gets detected.

I looked at the drive using:

1. Windows 7 Disk Management
2. Acronis Disk Director 11
3. EASEUS Partition Recovery (latest version)
4. Partition Wizard 5.2

None of them could do anything except delete or format the partitions. I saw no repair option or ability to mark the partitions as NTFS file system.

The partitions on my external drive are still there but no file system is shown for most of them. Acronis Disk Director shows the following information:

Disk 1 (GPT)
VOLUME CAPACITY FREE SPACE TYPE FILE SYSTEM STATUS
EFI 200 MB 200 MB Basic GPT FAT32 Healthy
Local Volume 232.9 GB 226.7 GB Basic GPT Unsupported Healthy
Unallocated 128 MB
Local Volume 232 GB 218.6 GB Basic GPT Unsupported Healthy
Local Volume 619.9 MB 130.1 GB Basic GPT Unsupported Healthy

I believe the partitions were originally created with the NTFS file system. My guess is that the partition table needs to be corrected to indicate that the partitions are NTFS. I'm not sure how to do this or how to rebuild the partition table. Is there anyway to repair the partition table and possibly access the data?
Thanks!

A big chunk is unallocated. Was some of your data there? If so try Partition Wizard Partition Recovery Wizard - Video Help.

See if PW can also run Partition Wizard Check File System which can recover some partitions that are not readable.

If not some success has been reported repairing the partition table using Disk Genius trialware: http://www.diskgenius.net/

I tried Partition Wizard Partition Recovery Wizard and it deleted all of the partitions but one. That one was empty so the data is gone. I just reformatted the drive.

Thank you for you help.

The drive in question is an external USB data-only drive that I use for backups. It has no Windows or other operating system on it. I will keep your suggestions for future use when I need to re-install Windows.

Thanks again for your help.