i recently picked up western digital 500gig external hard drive, is there a way to format a hard drive for windows vista and macs can use it ? i use macs and vista laptops just looking for advice?

it is a western digital my book essential edition 500gb external it has a green box i wonder if is one the newer models

Vista and OS X can both read and write FAT32 formatted disks.
Not at all sure how formatting works with a Mac but with Vista you can only create a partition up to 32Gb in size maximum. That means you'll need a whole lot of partitions there, 16 in fact.

There is a possible workaround - boot from a Win 98 disk and partition and format it from there which would allow larger than 32Gb per partition. Provided the disk would even recognize a 500Gb drive??

As you are more familiar with the Mac's capabilities perhaps the formatting solution would best come from there?

Of course there are the Western Digital Tools and 3rd party disk management tools to consider also.

stay with FAT32 and you should be able to read and write with both operating systems.

I agree with OEM_Guy, FAT32 is the best for compatibility. I'm not at my MAC atm and don't have time to look up the compatibilities of the File Systems, but I will see if I can get a chance and update you.

In the meantime, I should mention that Mac OS can READ NTFS and FAT32, but can only WRITE to FAT32 and HFS, etc.

Directly from the Compatibility section of the documentation for MAC OS X 10.4 (http://images.apple.com/business/pdf/MacOSX_Windows_TB.pdf):
Removable media and devices
A variety of other removable media and devices can be used to exchange files between
Mac and Windows systems, including Iomega Zip disks, USB disk-on-key devices, and
removable (external) FireWire and USB hard drives. For best compatibility, these devices
should be formatted using the FAT32 file system, which is supported by both Mac OS X
and Windows. Mac OS X also supports the ability to read files from devices that use the
NTFS file system format.

thank you very much

Glad we could help.