|  | Planning an Installation of Microsoft Windows XP Professional Choosing the Appropriate File System: FAT, FAT32, NTFS
| FAT and FAT32 Normally, you would not use FAT to format the partition on which Windows XP Professional resides because it does not have the file and folder level security that NTFS provides. However, if you do not require the security and compression features that are available with NTFS, or if you require a dual-boot configuration to run applications that are not compatible with Windows XP Professional, you might need to use FAT 32. FAT and FAT32 do not provide file and folder level security, and FAT does not support partitions larger than 2 GB. If you attempt to use FAT to format a partition larger than 2 GB, Setup automatically formats the partition with FAT32.
| Note: When you upgrade an operating system on an existing FAT or FAT32 partition to Windows XP Professional, you have the option to use NTFS or FAT32. If you choose NTFS, you can convert the partition to NTFS or format the partition using NTFS. If the partition contains data that you want to keep after the installation, do not format the partition. Instead, choose to convert the partition to NTFS to preserve the data.
| Important: Some operating systems, such as Microsoft MS-DOS® 6.22 or earlier, and Windows 95, do not recognize partitions that are formatted with FAT32 or NTFS file systems.