exFAT (Extended File Allocation Table, which also known as FAT64) is a proprietary file system introduced by Microsoft for embedded devices in Windows Embedded CE 6.0 and Windows operating system. exFAT file system is suited especially for flash drives, where NTFS file system is not a feasible solution due to data structure disk space overhead, which is greatly reduced in exFAT.

exFAT also improves over FAT with large files support of over 4 GB, large hard disk drive support of over 32 GB, and large files amount support of over 1000, which is important in view of larger and greater size of media files and multimedia contents. exFAT also enable seamless interoperability between desktop computers and devices, such as portable media devices. Because of this functionality, you can easily copy files between the desktop and external devices or between the desktop and other operating systems.

Microsoft adds support for exFAT file system natively into Windows operating system starting from Windows Vista SP1. For Windows XP users, exFAT support (or driver to mount a hard disk drive with exFAT filesystem) can be added to Windows XP with KB955704 hotfix.

KB955704 can be downloaded from Microsoft Download Center and installed into Windows XP SP2 or Windows XP SP3. Alternatively, directly download the WindowsXP-KB955704-x86-ENU.exe from Microsoft server.