Windows File Systems for CompTIA A+ 220-1102

NTFS is the default file system for Windows installations and internal hard drives. It supports files larger than 4 GB, per-file and per-folder permissions, file compression, and Encrypting File System (EFS). Max file size: 16 TB. Max volume size: 256 TB. Supports journaling (tracks changes before writing, enabling recovery after crashes). Required for Windows system drives. Supports hard links, symbolic links, alternate data streams, and disk quotas. NTFS permissions are granular: Full Control, Modify, Read & Execute, Read, Write, List Folder Contents. Permissions are inherited from parent folders by default but can be blocked. The Security tab in file Properties shows NTFS permissions.

FAT32 is an older file system compatible with nearly every OS and device. Max file size: 4 GB (hard limit — attempting to copy a larger file fails with an error). Max volume size: 2 TB (Windows format tool limits to 32 GB; third-party tools can go higher). No built-in permissions, encryption, or journaling. Universal compatibility: Windows, macOS, Linux, game consoles, cameras, TVs. Use case: USB drives, SD cards, devices that need broad compatibility. Limitation: cannot store ISO files, large video files, or VM images larger than 4 GB.

exFAT was designed as an upgrade to FAT32 for flash storage. Max file size: 128 PB (effectively unlimited). Max volume size: 128 PB. No permissions or journaling. Supported natively by Windows Vista SP1+, macOS 10.6.5+, Linux (via exfat-fuse or kernel 5.4+). Best use case: USB drives and SD cards that need to store files larger than 4 GB while remaining compatible with macOS. Often used for cameras and drones that output large video files.

NTFS permissions control who can access files and folders. Key permission levels: Full Control (read, write, modify, delete, change permissions, take ownership), Modify (read, write, delete; cannot change permissions), Read & Execute (view and run files), List Folder Contents (view folder contents without opening files), Read (view file content and properties), Write (create new files and subfolders, write to files). Effective permissions: combination of all permissions assigned to a user directly and through group memberships. NTFS permissions flow from share access down — the more restrictive of share and NTFS permissions applies when accessing over a network. Deny always overrides Allow. Inheritance can be disabled per folder (Advanced Security Settings → disable inheritance).

EFS is a built-in NTFS feature that encrypts individual files and folders at the file system level. EFS uses a certificate tied to the user account. When EFS-encrypted files are opened by the authorized user, they are transparently decrypted. Other users (even admins) see encrypted gibberish without the certificate. Key EFS facts: file color changes to green in Windows Explorer. EFS certificate must be backed up (certmgr.msc → Personal → Certificates → export). If the certificate is lost and the user account is deleted, EFS files become permanently unrecoverable. EFS is NOT available on Home editions of Windows — requires Pro or Enterprise. BitLocker encrypts the entire drive; EFS encrypts individual files. They can be used together.

To convert FAT32 to NTFS without data loss: `convert C: /fs:ntfs` (command prompt as administrator). There is no built-in convert from NTFS to FAT32 — requires backup, format, restore. Format options in Windows: right-click drive in File Explorer → Format. Disk Management (diskmgmt.msc) for more options. Quick format: marks space as available without wiping data (recoverable). Full format: writes zeros to every sector, verifies surface. diskpart command-line tool: `select disk X`, `select partition Y`, `format fs=ntfs label=MyDrive quick`. NTFS allocation unit size (cluster size): default 4 KB for most cases. Larger clusters improve performance for large files but waste space for small files.

Windows NTFS: macOS can read NTFS natively but write support requires third-party drivers (Paragon NTFS, Tuxera). Linux reads and writes NTFS via ntfs-3g driver. ext4 (Linux native file system): Windows cannot read ext4 without third-party software (ext2fsd, Linux Reader). exFAT is the recommended cross-platform format for drives shared between Windows, macOS, and Linux. HFS+ and APFS (macOS native): Windows cannot read these without third-party software (HFSExplorer, Paragon HFS+).