Help! Installing External Drive on Old Tiger Mac


I'm using an old eMac with Tiger, and have connected a WD Passport external hard drive, a very small one. I reformatted the drive with the help of WD's support line, but seem to have a problem transferring my iPhoto library to the Passport; it stops transferring info when it runs into a given photo, saying that the particular photo is in use. I'm not a technical person, and there's no Tiger update for the Passport drive, and the only things the drive needs to protect is My Documents and iPhoto. Can someone tell me how to go about this simply? I could really use some advice here. Thanks for reading. Sincerely, Sparrowhawk.
Try the backup again, and see if you can prevent that photo from being in use:
Boot the eMac holding the shift key, which will mean that you boot to Safe Boot mode. That will keep most apps that boot with your normal system from starting up. And, the copy should proceed without complaining.
Your hard drive may have some problems with the file directory, so if the copy still fails, test your hard drive by running fsck from single user mode.
Do you need help with that?
Also, it may be prudent to check and see what format the external drive is in. For maximum compatibility with your Mac and Mac-style filenames and attributes, it should have:

1) An "APM" partition scheme
2) A drive format of "Mac OS Extended"

It's likely (but not guaranteed) that Western Digital had you format the drive as FAT32, which has some limitations.