You will need to format any drive before you can use it.
As you probably know there are different kinds of file system used by computers XP can use NTFS or FAT
Win 98/ ME can only use FAT.
Macs use something different I believe. Formating is done by the operating system to beable to use the drive.
Defrag and run check disk on the old drive it will help to reduce the SMART erors.