If Backup for Workgroups is configured to store your backup data on a hard drive that has been formatted as FAT32, you may run into a problem storing backups of large files. Most USB and FireWire external hard drives are preformatted as FAT32. FAT32 cannot store a file that is larger than 4GB.
If you plan to backup files that are larger than 4GB, you will need to convert a FAT32 drive to NTFS. Windows comes with a utility that will convert a FAT32 drive to an NTFS drive without requiring you to reformat the drive first, so you do not lose any of your data that you may have stored on this drive.
Start this process at a convenient time when you can re-boot your computer and have it off-line for up to an hour.
Open a command prompt (a DOS shell).
CONVERT X: /FS:NTFS
Where X: corresponds to the FAT32 drive.
When you initiate the CONVERT program, it is typical for Windows to delay the conversion process until the next time you re-boot the computer. At that time, the conversion will occur, which will delay the boot process while the conversion process is running. During this time, your computer will be off-line.