When Does 0x00000027 Show Up?
You're copying a file—maybe a 10 MB PDF, maybe a project folder—and Windows throws ERROR_HANDLE_DISK_FULL (0x00000027). You check the drive properties: plenty of free space. Yet the copy fails. This error doesn't mean "buy a bigger drive." It means something inside the file system is lying.
Common triggers:
- Copying to an external USB drive after a sudden unplug or unsafe ejection.
- After a Windows update that rebooted the machine but left the drive in a weird state.
- On a system drive (C:) when you've been running virtual machines or editing large videos—heavy shadow copy usage.
- Inside a corporate environment where disk quotas are enabled but the quota limit is smaller than the drive's physical space.
Root Cause: NTFS Metadata, Shadow Copy, or Quota—Not Actual Free Space
The error code 0x00000027 maps to ERROR_HANDLE_DISK_FULL. But what's actually happening is one of three things:
- NTFS metadata corruption. The Master File Table (MFT) has a bad record about how much space is really free. This happens when a drive was disconnected during a write operation. The file system thinks it has less free space than it does.
- Volume Shadow Copy store is full. Shadow copies—used by System Restore and backup tools—reserve a fixed percentage of the drive. If that reserved pool is full, Windows sees a write request and refuses, even if the rest of the drive has space. The error is technically correct: the shadow storage area is full.
- Disk quota limit hit. An admin set a per-user quota smaller than the actual free space. Your application asks "how much space is left?" and the OS answers "quota remaining," which is zero.
On Windows 10 22H2 and Windows 11 23H2, we also see this after a failed BitLocker unlock—the drive shows free space but the volume is locked and can't allocate new clusters. That's a fourth case, but rarer.
Step-by-Step Fix
Step 1: Check Disk Quotas First (Saves Time)
Skip this if it's your personal machine. But if you're on a domain-joined laptop, open a command prompt as admin and run:
fsutil quota query C:If you see Quota limit: 5000000000 (5000 MB) and the drive has 200 GB free, that's your problem. Talk to your IT admin or run fsutil quota modify C: 4294967295 4294967295 to disable it (but you'll need admin rights).
Step 2: Check Volume Shadow Copy Usage
This is the most common cause on personal machines. Run this in an admin command prompt:
vssadmin list shadowstorageLook for the line Used Shadow Copy Storage space. If it's close to Allocated Shadow Copy Storage space, you're out of shadow copy room. The fix is to reduce the max size:
vssadmin resize shadowstorage /on=C: /for=C: /maxsize=10%This sets max shadow copy usage to 10% of the drive. Windows deletes old shadows to comply. Run the copy operation again. Nine times out of ten, it works.
Step 3: Run chkdsk to Fix NTFS Corruption
If the above didn't help, the MFT is likely busted. Run:
chkdsk C: /f /rThe /f flag fixes errors; /r locates bad sectors and recovers readable data. On a system drive, it'll schedule a check on next boot. Reboot and let it run. It can take an hour on a 1 TB drive. Don't interrupt it.
The reason step 3 works even if step 2 didn't is that chkdsk rebuilds the $Bitmap file—the actual map of free clusters. If that map says a cluster is in use but it's not, that shows as "full" to the handle allocation function. chkdsk corrects the map.
Step 4: Check for Ransomware or Hidden Large Files
Yes, sometimes the error is literal: Windows just can't see the files eating space. Use a tool like TreeSize Free or dir /s /a from the root. Look for a folder named System Volume Information—that's the shadow copy store. If it's enormous (over 30 GB on a 256 GB drive), you can clear it by disabling System Restore temporarily:
Disable-ComputerRestore -Drive "C:\"
# Reboot, then re-enable:
Enable-ComputerRestore -Drive "C:\"This wipes all restore points. Only do this if you're okay losing them.
Step 5: Third-Party Antivirus or Filter Driver
Some AV software (especially older McAfee or Norton) installs a file system filter that intercepts write requests. If the filter's own memory buffer is full, it can report back "disk full" even when the disk has space. Temporarily disable the AV's real-time protection and try the copy again. If it works, update or replace the AV.
What If It Still Fails?
If none of the steps cleared the error, the disk may have genuine hardware problems—not just logical ones. Check the S.M.A.R.T. status:
wmic diskdrive get statusIf it returns anything besides OK, replace the drive. A failing drive can misreport its free space as the firmware starts losing track of bad sectors.
Also, test with another system: plug the drive into a different computer. If the error follows the drive, it's a hardware fault. If it doesn't, the issue is OS-specific—something in the driver stack or registry. In that case, a Windows repair install (keep files) is the nuclear option.
One last thing: if you see this error on a virtual machine's virtual hard disk (VHDX), the host may have run out of host-side space. Check the physical host's drive, not just the guest.