Read this instructions my friend
It is possible to use a Western Digital external hard drive on botha PC and a Mac. However, there are some things to keep in mind if youwant to do this. Moreover, Western Digital does not recommend doing it.
- For both PC and Mac to be able to read the drive, it must beformatted in the FAT32 file format. In order to format to FAT32 on aMac you may need to contact Apple for support. We do have a FAT32Formatting utility for Windows that reformats WD external hard drivesto their full size, but in only one partition. The FAT32 formattingutility can be downloaded from our Downloads Library. You will find it on your WD drive's Downloads page.Critical: Do not attempt toconnect any external drive to multiple computers, simultaneously; letalone to both a Mac and PC. This could quickly damage the drive'spartition and corrupt the data on the drive.
- Sometimes, PC's won't read Mac FAT32 formatted drives, andMac's won't read PC FAT32 formatted drives. You may have to re-formatthe drive trying both the PC and Mac until you get a format that works.
- Most WD external hard drives come pre-formatted with one large FAT32 partition, which is accessible by Windows 2000, XP, and Vista, and Mac OS 10.4 and 10.5.
- Windows 2000, XP and Vista can only create FAT32 partitions that are 32 GB's or smaller.
- Mac 10.4 and 10.5 can create FAT32 partitions the full size of the drive.
- There is a 4 GB file size limit on the FAT32 file format. Thisis a file system limitation that affects both Mac's and PC's, and thereis no way around it.
- Finally, you need to understand that if you are using the samedrive back and forth between a Mac and PC, there is always the chanceof files being corrupted. Mac's and PC's are different platforms, andtheir file systems function differently. Please keep backups of allyour files before you start sharing between Mac and PC computers.
Once the data iscorrupted, that drive may no longer be recognized by one or both of thecomputers. Or, the drive may be recognized, and the data may bevisible, but you won't be able to open any files. At that point, youwill need to re-partition and reformat the drive in order for it to berestored and usable by both computers again. In the process, you willlose all the data on the drive. For that reason, you need to keep abackup of the files you are transferring between computers.At the bottom of the page, you will find links for partitioning and formatting in Windows XP
and Vista, and Mac 10.4 and 10.5.