Windows drive letters are not limited to A-Z

Original Article ↗ Hacker News Discussion ↗

NT internals vs DOS façade

  • Commenters highlight how Windows NT’s kernel and object manager are far more general than the A–Z drive-letter UI suggests.
  • Drive letters are just symbolic links in the \?? namespace; anything named like C: there behaves like a drive. NT paths (e.g. \Registry\Machine) form a global object tree, similar in spirit to a Unix VFS.
  • Explorer’s COM/GUID mechanisms and shell folders are cited as another “magical” layer on top, enabling things like “God Mode” folders and deep links via CLSIDs.
  • PowerShell extends the “drive” concept to non-filesystem providers (registry HKLM:\, certificates Cert:\, SharePoint, etc.), exposing structured OS state as if it were a filesystem.

Unicode / nonstandard drive letters

  • The article’s examples (e.g. €:\, +:\, Λ:) prompt discussion of codepages, UTF‑16, and whether non‑ASCII drive letters behave consistently with “ANSI” APIs; some say they do, others argue older APIs may break.
  • People joke about emoji drive letters; technically the kernel likely could handle some, but Explorer and UTF‑16 surrogate pairs would limit options.

Security and malware concerns

  • Several see this as fertile ground for malware: odd drive letters, hidden mounts, RAM disks, and obscure NT volumes could confuse AV and analysis tools.
  • Others counter that admin rights are required, scanning can still target underlying volumes, and there are already stronger evasion tricks (e.g. NTFS Alternate Data Streams, “mock” folders, registry name quirks).
  • Past tricks like invisible directories (ALT+255 names) and registry keys that standard tools can’t open are mentioned as precedent.

Mount points, NTFS features, and UI gaps

  • Multiple comments stress that Windows isn’t truly limited to drive letters: volumes can be mounted into directories, NTFS mount points and symlinks exist, and volume GUID paths (\\?\Volume{…}\) work.
  • These capabilities are available via Disk Management or PowerShell, but are under-advertised, leading users to think only in terms of C:, D:, etc.

History, usability, and comparisons

  • Long subthreads reminisce about floppies (A:, B:), early hard disks (C: as “luxury”), CD‑ROMs on D:, and Netware/Xbox-style extended “drive” names.
  • Many criticize drive letters as archaic and error-prone (e.g. backups to the wrong USB letter); others defend them as valuable backward compatibility.
  • Comparisons with Linux focus on /dev instability, UUID-based mounts, FHS cruft, and Plan 9’s “everything is a file” as a cleaner conceptual model.