Windows drive letters are not limited to A-Z

Windows can have '+:\' and '€:\' drives — geeks cheer, pranksters plot, Explorer cries

TLDR: Windows can map drives beyond A–Z (even +:\ or €:\) via hidden path tricks, but File Explorer won’t show them. Commenters split between excitement over Windows’ flexibility and warnings about prank or malware potential—while emoji-drive dreams got roasted—making this a quirky, useful peek under the hood.

The internet just learned Windows isn’t stuck with A–Z, and chaos ensued. A cheeky demo with subst showed you can make a drive called +:\ that works in the command line, thanks to Windows’ backstage “object manager” that quietly remaps friendly paths to deeper system routes—think a secret hallway behind C:.

Reactions were instant and spicy. “The cursedness of ‘€:\’ is awesome,” cheered one commenter, celebrating how flexible Windows really is compared to the tame surface we use. Another slammed the brakes: “This sounds like a wonderful way to write some truly annoying malware,” predicting hidden mounts and prank drives named like database injection gobbledygook. A nostalgic side plot popped up with talk of the Xbox 360’s weird drive letters and an alternate universe where FOO:\ is totally normal.

But reality bites: File Explorer won’t show these offbeat drives, so your emoji hard drive dreams are crushed. “Well there goes my plan to replace all my drive letters with emojis,” sighed a user. The thread split into camps: power users thrilled by the secret map, security folks warning about trickery, and curious onlookers just delighted to learn a new party fact. Verdict: Windows is weirder—and cooler—than you thought, even if WinObj is the only one truly impressed.

Key Points

  • Windows drive identifiers can be created beyond A–Z, e.g., using subst to map +:\ to C:\foo.
  • Win32 paths (like C:\foo) are translated into NT namespace paths (\??\C:\foo) before NT-layer calls.
  • NtTrace shows CreateFileW results in NtCreateFile with ObjectAttributes set to an NT path.
  • In the Object Manager, C: in \GLOBAL?? is a symlink to \Device\HarddiskVolume4, resolving \??\C:\foo.
  • Volumes expose GUID-based objects, making \??\Volume{GUID}\foo equivalent to \??\C:\foo.

Hottest takes

"The cursedness of '€:\' is awesome" — thrtythreeforty
"a wonderful way to write some truly annoying malware" — azalemeth
"replace all my drive letters with emojis" — RobotToaster
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