Reformat
What Format?
In the Finder, find your external hard drive. Select the icon and go File->Get Info. In the window, under "General" you should see "Format:". If that format is NTFS, then this disk will NOT work with kJams. (NTFS is read only and kJams requires write access to your music files.) You will need to reformat that drive. To do that, you'll need to back up all the data on the drive, that means you'll have to have another drive which is at LEAST as large as this drive. Copy all your data on to the other drive, reformat, then copy it back.
If that format is FAT32, the drive WILL work with kJams, *and* will also work with Windows. You'll be able to plug the drive into either a Mac or a PC and be able to transfer files back and forth. However, you will not get the very best performance.
If that format is "Mac OS Extended (Journaled)" (which is another name for "HFS+"), then you will get the best performance, but you can not share that drive with a Windows computer unless you have a File System plugin that can read/write Mac OS format.
How to Reformat
- back up all your data on another drive
- launch /Applications/Utilities/Disk Utility