Format big FAT32 disk (larger than 32GB)
As Microsoft put it here:
You cannot format a volume larger than 32 gigabytes (GB) in size using the FAT32 file system during the Windows XP installation process. Windows XP can mount and support FAT32 volumes larger than 32 GB (subject to the other limits), but you cannot create a FAT32 volume larger than 32 GB by using the Format tool during Setup. If you need to format a volume that is larger than 32 GB, use the NTFS file system to format it. Another option is to start from a Microsoft Windows 98 or Microsoft Windows Millennium Edition (Me) Startup disk and use the Format tool included on the disk.
However there is a solution to this, using the free command-line tool fat32format. If you see some message saying:
Failed to open device – close any files before formatting Are you SURE you’re formatting the RIGHT DRIVE!!!
then try rebooting and make sure you don’t open any view to the disk you want to format using Windows Explorer. If the message still comes up then try this suggestion from the program’s author:
Incidentally, if you are running admin and it still complains about open files, you can use Process Explorer to find out which process is guilty. Run it, Press Ctrl+F and enter the drive letter, e.g. E: and close any processes that have it open