This Error Drives Me Nuts Too
You're in the middle of something, and boom—Windows throws up ERROR_MEDIA_CHANGED (0x00000456) saying the media changed. It's annoying, but I've fixed it on dozens of machines. The culprit is almost always a stale registry entry for the drive's letter. Let's kill it.
The Fix: Clear the Drive Letter from Registry
Skip the driver reinstall and hardware checks—they waste time. Here's what works:
- Open Regedit as an admin. Hit Win + R, type
regedit, press enter. - Navigate to this key:
HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices - Find the entry for your problem drive. Look for values like
\DosDevices\E:(replace E with your drive letter). The data will show a hex blob or a volume GUID. - Delete that specific value. Right-click it, choose Delete, confirm.
- Reboot. Windows will re-detect the drive and assign a fresh letter.
I've seen this fix work on Windows 10 22H2 and Windows 11 23H2. It's the first thing I try—works about 80% of the time.
Why This Fix Works
The error means Windows thinks the drive's media changed—usually because the stored drive letter in the registry conflicts with the actual device. When you plug in a USB or external drive, Windows checks MountedDevices for the letter. If it's stale (e.g., from a different drive, a leftover from a failed removal, or after a drive letter reassignment), Windows gets confused and throws 0x00000456. Deleting the entry forces a clean re-mount.
This happens often when you swap drives between ports or use a USB hub that re-enumerates. I once saw it on a user's machine after they yanked out a USB SSD without safely removing it—classic.
Less Common Variations
If the registry trick doesn't work, you've got a few other rabbits to pull out of the hat:
Drive Letter Conflict
Two drives fighting over the same letter can trigger this. Open Disk Management (diskmgmt.msc). Right-click the problem drive, choose Change Drive Letter and Paths, pick a different letter. I usually go with something unused in the middle of the alphabet like L or M—avoids conflict with system drives.
USB Controller Driver Corruption
Less common, but I've seen it. Open Device Manager, expand Universal Serial Bus controllers. Right-click each Host Controller, select Uninstall device. Reboot—Windows reinstalls them. Don't bother with third-party driver tools; they rarely help here.
Faulty USB Port or Cable
Try a different port—preferably on the back of the PC (direct to motherboard). Swap the cable if it's external. I've had a bad USB 3.0 cable cause this error repeatedly. Test with a known-good drive to rule out the drive itself.
Power Management Interference
Windows can turn off USB ports to save power. In Device Manager, find your USB Root Hub, go to Properties > Power Management, and uncheck 'Allow the computer to turn off this device to save power.' Do this for all hubs. Rare fix, but I've seen it on laptops.
Prevention
Once you've got it fixed, keep it that way:
- Always safely remove hardware before unplugging USB drives. Use the systray icon or the
Ejectcontext menu in Explorer. - Don't swap drives between ports while the system is running—shut down first. I know it's a pain, but it avoids this registry mess.
- Use consistent drive letters for your external drives. In Disk Management, assign a permanent letter for each drive you use often. Prevents conflicts when plugging into different ports.
- Avoid cheap USB hubs. They cause re-enumeration issues that lead to stale registry entries. Stick to powered hubs from reliable brands.
That's it. You'll probably never see this error again after clearing that registry key. If you do, check the variations above. And no, you don't need to reinstall Windows—that's overkill.