Entire libraries have been written about file systems but all we want to know is which should we choose for a particular operating system or that data partition or device we want to share across different platforms. In this article we cover how to format, then look at the recommended uses and limitations of the available files systems.

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In fig:1 we have one hard drive with three primary partitions and one logical. To reformat a partition click or right-click on it so that it becomes partially shaded, which will confirm it will be the focus of any operations about to be performed. From the right-click popup menu select Format. (Your popup menu may have less or more options than shown here depending on which version of Windows and Disk Management you are using)

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The options dialog box you will have called up (fig:2) has a couple of settings that the average PC user should leave well alone. Don't change the Allocation unit size from Default and do not turn on file and folder compression. In Windows-7 the quick format option will already be ticked but in previous versions of Windows you will have to tick the box yourself if you wish to skip the sector check. (You can cancel out of a format and re-start if you realize you have inadvertently left the box unchecked). The Volume Label can be changed and we would suggest that you give partitions descriptive names to help uniquely identify them and remind yourself what they contain.

The important thing of course is the File System option, so click on the appropriate drop-down box to be shown the possible choices allowed for the partition or device you are working on. The available options will only be the Windows supported file systems of FAT, FAT32, NTFS and perhaps the new exFAT (fig:3).

Fig: 4

If the partition you are formatting currently has a drive letter then clicking OK to proceed might bring up the following warning box.

Formatting an existing partition is almost the same as deleting and recreating it and so any links an operating system has to the partition or its data will be lost. Even if you do not get this second warning box you should if the partition has a drive letter make sure there is nothing on it you may want to retain. If you are unsure then we suggest you only remove the drive letter and run your machine for a few days to see if the missing drive is going to reveal any problems. Much of what is discussed in the section Drive in Use? for deleting partitions is also relevant here.

If you proceed with formatting then the only clue that something is happening will be the one word message on the partition in question (fig:6), but with a quick format it may last only briefly or not even have time to appear. If running a sector check at the same time then there will also be a percentage figure readout of progress to give some idea of how long it is likely to take.

In our example we reformatted a partition to the same file system just as a way of wiping the slate clean and preparing the partition for reuse. If the partition is going to be used for a new install of an operating system then the formatting could just as equally be done from options during the install of that operating system. Indeed sometimes it can be better to let an OS do its own formatting of a partition or device as it will undoubtedly know which file system or which version of a file system is best suited to itself.

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Other Devices.
The Windows Disk Management utility can be used on externally connected hard drives and will offer most of the range of functions that are available for internal drives. For USB and SD flash devices however it will be limited like Windows itself to recognizing and working with only the first partition on the device, any extra partitions being unseen by Windows and untouchable by Windows disk tools like Disk Management.

There have been 5 versions of NTFS since 1993, but version v3.1 that first appeared in XP in 2001 has continued all the way thru to Windows 8. Successive operating systems since XP have added some extra features to their own implementation of the file system, but don't confuse version numbers of operating system NTFS drivers with the core on-disk version of the underlying NTFS file system. http://en.wikipedia.org/wiki/NTFS

Uses:
Microsoft NTFS is the sole choice for the new generation of Windows NT operating systems and is also recommended by MS for all hard drive data partitions. The pre-Vista generation of WinNT operating systems are also recommended to use NTFS but they will work on FAT32 if you need them to.

Limitations:
Cross platform compatibility with other operating systems is not absolute. Most notably Mac and some Linux can't natively write to NTFS partitions and even when support is added there can be restrictions. While it can be used on Flash devices and will perform well it has overheads that require extra read/writes, which may impact on the life span of a flash device. The Safely Remove Hardware option must be used to remove an NTFS flash device to avoid a high probability of data corruption. The Disk Management tool in WinXP won't offer NTFS as a formatting option for flash devices, but it can be done from the XP Format Tool if the device has first been enable for write caching.

The FAT file system offered by Disk Management is actually FAT16 and it will only be shown as a possible formatting option if the partition or device is under 4gigs in size.

Uses:
Typically these days it would only be used on hard drives for a small DOS or bootmanager partition, but it is common on flash storage devices that are under 4gigs, where it performs on a par with or better than FAT32. It has near universal cross platform support which allows compatibility and sharing of data with non-Windows operating systems and devices that take flash sticks or memory cards.

Limitations:
A partition formatted in FAT16 can be a maximum of 4gigs in size, but earlier Windows operating systems such as Win95 to WinME and MS-DOS have a FAT16 partition size limit of only 2gigs. The maximum number of individual files possible are 65536. Maximum individual file size is not limited other than to the actual partition size.
Maximum Partition Size Using FAT16 File System in Windows XP - Microsoft KB310561

Disk Management and other MS formatting tools since XP will only offer FAT32 as an option if the partition or device is under 32gigs in size. The Windows OS itself is not bound by this restriction and can handle FAT32 partitions up to any size that is supported by the hardware. If you want to format partitions larger than 32gigs then you could either use an earlier Microsoft utility or a third-party tool such as Partition Wizard or one of these small apps.

Uses:
Windows operating systems from pre-Vista and back to the later versions of NT4 and Win95 can be installed on a Fat32 partition of any size that the OS and hardware supports. About the only time you would use it now for XP or 2K would be if you didn't want any of the file permission restrictions or performance overheads of the NTFS File system. The most common uses for FAT32 would be for a data partition or drive that is required to be shared with an operating system that has problems with NTFS, or for flash devices that are above 4gigs in size. It has almost universal cross platform support which currently makes it the file system of choice for most flash devices that have to be compatible with a range of operating systems and devices.

Limitations:
Lacks file permission security features and can't be used with bitlocker drive encryption. But its main limitation would be the maximum size of a single file can be no more than 4gigs, which has no doubt caught a few people out in recent years with the ever expanding size of some media files and the requirements of VHD files.
Limitations of the FAT32 File System in Windows XP - Microsoft KB314463
   Description of the FAT32 File System - Microsoft KB154997

Microsoft’s new exFAT (extended FAT) file system is primarily aimed at replacing FAT32 on flash and external storage devices. It does away with the 4gig file size limit of FAT32 and it does not have the overheads of the NTFS file system that can reduce the life span of flash media.

Only Windows7/8 and Vista-SP1 are natively able to see and support exFAT formatted devices, and only the Disk Management tools in those operating systems are capable of formatting in this new file system. Vista will only let you reformat existing partitions on external flash and USB connected drives, but in Windows7/8 you can create new exFAT partitions over 32gigs (32760gb) on any MBR device, but you still can't reformat existing partitions on internal drives - either HDD or SSD, (say what?). You cannot create exFat partitions under 32gigs on any device, but you can reformat any size of partition to exFat on external drives and flash devices. Only Win-8 currently supports formatting exFat on GPT styled hard drives.

You can add support for exFAT to XP and the original Vista so that they can see and work with exFAT formatted partitions and devices. The update does not however add support to XP's Disk Management, but it does add support into the Windows Format Tool so you can use that to format in exFAT on internal and external hard drives and flash devices.
exFAT file system driver update package

Uses:
Primarily designed for flash sticks, cards and devices but can be used for data partitions on both internal and external hard drives. May be a better bet than NTFS for a data partition shared with non-Windows operating systems. Mac Os X added full read/write support in late 2010. An exFAT partition cannot be used to install Windows to, (not yet anyway).

Limitations:
Reportedly has less fault tolerance than FAT32 and can't use the security features of NTFS file permissions, but partial support may be added in later versions. The main limitation at the moment is simply lack of support across operating systems, devices that use flash media, and software that needs to recognize file systems. In our own little area of interest that means things like third-party partitioning, imaging and cloning tools and bootmanagers.
http://en.wikipedia.org/wiki/ExFAT   An Introduction To exFAT   Hands-on with exFAT

For an install of Vista and Windows-7/8 then you have no option but to use NTFS. You should choose the same for XP/2K unless there is a specific reason you require FAT32. For a shared data partition or backup drive then again you would go with NTFS unless you require write ability by an operating system that does not fully support NTFS. In which case FAT32 would be the choice because of its cross platform support and known dependability. If the 4gig maximum file size limit in FAT32 is going to be an issue then you could experiment with exFAT if it is supported by all the operating systems that need to directly access the partition. At time of writing this is only Windows, and Mac OS X from v10.6.5.

USB flash sticks and memory cards under 4gigs can be either FAT16 or FAT32 and there is no real consensus on which one is best, but if speed is an issue then FAT16 may have a very slight edge in some situations. If the device is over 4gigs in size then it should be FAT32, unless you foresee issues with the 4gig maximum file size limit. In which case exFAT can be used, bearing in mind that it won’t be recognized by operating system and devices such as cameras, TVs, phones etc that don’t have exFAT support. The NTFS file system is not recommended for flash media but it does perform adequately and as long as you don’t need full cross platform support and you are aware of the life-span issue, then it may work for you.

Of course you don't need to use a Windows file system if you don’t need cross platform support.
Which is the best Linux filesystem for USB devices?
Format an External Hard Drive or USB Flash Drive for Mac OS X