Windows

The main filesystem used by Windows is NTFS. As well as being case-insensitive, the signature feature that distinguishes Windows FS from others is the use of a letter followed by a colon to represent a partition in paths, combined with the use of backslash as a folder separator, instead of a forward slash. Drive letters, and the use of C for the primary partition, comes from MS-DOS, where A and B were reserved drive letters used for floppy disk drives. 

Windows also natively supports other filesystems, such as FAT, which is a filesystem family that was very popular between the late seventies and the late nineties, and Extended File Allocation Table (exFAT), which is a format developed by Microsoft on top of FAT for removable devices.