Editing Disk partitioning (section)

=== Primary partition ===
{{Further|Partition type}}
A primary  partition contains one file system. In [[DOS]] and all early versions of [[Microsoft Windows]] systems, [[Microsoft]] required what it called the [[system partition]] to be the first partition. All Windows operating systems from Windows 95 onwards can be located on (almost) any partition, but the boot files (<code>io.sys</code>, <code>bootmgr</code>, <code>ntldr</code>, etc.) must reside on a primary partition.  However, other factors, such as a PC's [[BIOS]] (see [[Booting#Boot sequence|Boot sequence on standard PC]]) may also impose specific requirements as to which partition must contain the primary OS.

The partition type ''code'' for a primary partition can either correspond to a file system contained within (e.g., {{mono|[[Partition type#PID 07h|0x07]]}} means either an [[NTFS]] or an OS/2 [[High Performance File System|HPFS]] file system) or indicate that the partition has a special use (e.g., code {{mono|[[Partition type#PID 82h|0x82]]}} usually indicates a Linux ''swap'' partition). The [[FAT16]] and [[FAT32]] file systems have made use of a number of partition type codes due to the limits of various DOS and Windows OS versions. Though a Linux operating system may recognize a number of different file systems ([[ext4]], [[ext3]], [[ext2]], [[ReiserFS]], etc.), they have all consistently used the same partition type code: {{mono|[[Partition type#PID 83h|0x83]]}} ([[file system#Linux|Linux native file system]]).