Windows 11 & 10 Backup Never Finishes? Fix Drive, VSS and File History Errors

Important: Windows 10 reached end of support on October 14, 2025. The steps below still apply to PCs running Windows 10, but an unsupported operating system should be upgraded or otherwise managed appropriately after the backup problem is resolved.

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Identify the backup type and preserve the failed backup​

Before deleting anything, identify what is actually failing:

• File History: Open Control Panel > System and Security > File History.
• Backup and Restore (Windows 7): Open Control Panel > System and Security > Backup and Restore (Windows 7).
• Third-party backup software: Open its backup history or log and note the exact error, error code, source volume, and destination drive.
• Windows Backup: Open Settings > Accounts > Windows backup. If the issue concerns OneDrive folder backup or account synchronization, use OneDrive and account troubleshooting rather than the VSS steps below.

Do not remove an existing destination drive or erase its contents just because a backup failed. An incomplete backup may still contain older, recoverable backup versions.

If the backup reports an error, take a screenshot or write down the full wording before retrying. “Backup could not be completed,” “cannot create a shadow copy,” “VSS,” “I/O device error,” and “destination unavailable” point to different causes.

Check that the backup destination is available and healthy​

A disconnected USB drive, unstable cable, full destination, or file-system problem can make a backup appear to hang because Windows or the backup program is repeatedly retrying reads and writes.

1. Confirm the drive is still connected and has a stable letter​

1. Connect the external drive directly to the PC if possible. Avoid USB hubs, front-panel ports, and adapters while troubleshooting.
2. Open File Explorer with Windows key + E and select This PC.
3. Confirm that the destination drive appears under Devices and drives and has the same drive letter used by the backup job.
4. Open the drive and create a small test folder, such as BackupTest.
5. Copy a small, unimportant file to that folder, then delete it.

If Windows cannot create, copy, rename, or delete a test file on the drive, fix the drive problem before working on VSS. Try another USB port and, if available, another known-good cable. For a portable hard drive, use its original cable where possible.

If the backup job expects a particular drive letter but the drive now has another letter, update the backup program’s destination setting rather than assuming it will find the drive automatically.

2. Check free space on both the destination and the source drive​

1. In File Explorer > This PC, check the free-space figure shown below:
   • The backup destination drive.
   • The system drive, usually C:.
   • Any additional drive included in the backup.
2. Right-click the destination drive and select Properties for a more detailed capacity and free-space view.
3. On Windows 11 or Windows 10, you can also open Settings > System > Storage to review usage on local volumes.

A destination drive needs enough space for the backup data it is being asked to hold. A system-image or versioned backup may need substantially more space than the files changed since the last run. The source drive also needs working room: VSS creates a point-in-time snapshot before a VSS-aware backup can read consistent files.

Do not assume that deleting only the newest incomplete folder will solve a space problem. Some backup products maintain catalogs, retention chains, or incremental sets that depend on older files. Use the backup application’s own cleanup, retention, or “manage space” feature when it has one.

3. Check the drive’s file system and run a read-only scan​

1. In File Explorer, right-click the backup destination drive and select Properties.
2. On the General tab, note the File system entry.
3. Select the Tools tab.
4. Under Error checking, select Check and follow the prompt.

For a more explicit diagnostic, open an elevated Command Prompt:

1. Search for Command Prompt.
2. Select Run as administrator.
3. Replace E: below with the actual backup-drive letter, then run:

chkdsk E:

This checks the volume and reports its status without repairing it.

If the drive is formatted with NTFS, you can run an online scan:

chkdsk E: /scan

Expected result: Windows reports the file-system status or identifies errors requiring repair.

Warning: Do not start with chkdsk /r on a large external drive unless you have reason to suspect physical media trouble and can leave the PC and drive connected for a long time. It reads the disk extensively and can take hours. Do not disconnect a drive while any CHKDSK operation is running.

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If the scan finds file-system errors, repair the external destination while no backup is running:

chkdsk E: /f

The /f option repairs file-system errors and requires administrative rights. Close every File Explorer window and program using the destination drive first. If Windows cannot lock the volume, stop and make sure the backup application is closed; do not force a repair while a backup is actively writing to the disk.

If the destination drive repeatedly disconnects, reports I/O errors, makes unusual sounds, or CHKDSK finds recurring errors, treat the drive as unreliable. Copy any accessible backup data to another healthy drive before relying on it again.

Check File History or the configured backup destination​

File History on Windows 10 and Windows 11​

File History still uses the Control Panel interface on both versions.

1. Open Control Panel.
2. Select System and Security > File History.
3. Confirm that the expected external drive or network location is shown.
4. If the wrong destination is selected, choose Select drive, pick the correct location, and select OK.
5. If File History is enabled, select Run now to start a manual test backup.

If File History asks whether to move existing files when selecting a new location, choose carefully:

• Choose to move existing files only when the new destination is intended to continue the same File History set.
• Start fresh only when you understand that older File History versions on the prior destination will no longer be part of the active history.

Backup and Restore (Windows 7)​

1. Open Control Panel > System and Security > Backup and Restore (Windows 7).
2. Review the destination listed beside the backup configuration.
3. Select Change settings only if the destination is unavailable, full, or no longer appropriate.
4. Verify that the selected backup items do not include the destination drive itself.
5. Run Back up now after the drive checks are complete.

A backup target must not be one of the volumes being backed up. If a system-image or command-line backup is configured to include a volume while also targeting that same volume, choose a separate destination drive.

Test VSS writers before changing services​

VSS coordinates the snapshot used by many image backups and third-party backup programs while Windows and applications are still running. A failed VSS writer can stop a backup before the file-copy phase begins.

1. Save open work and close the backup application.
2. Restart Windows. This clears many temporary writer failures and releases files left open by a failed backup.
3. After sign-in, open Command Prompt as administrator.
4. Run:

vssadmin list writers

Expected result: Windows lists one or more writers. Each writer should normally show:

State: [1] Stable
Last error: No error

Do not run the backup yet if one or more writers show a failed state or a nonzero last error. Record the writer name and error first.

Next, check VSS shadow-copy storage:

vssadmin list shadowstorage

This displays the volume being shadowed, the volume holding shadow-copy storage, and the currently used, allocated, and maximum storage values. If the system drive or the shadow-copy storage volume is critically low on free space, free space there before retrying the backup.

Verify VSS-related services without changing normal startup settings​

VSS services are commonly configured to start on demand. A service shown as Manual is not automatically broken and should not be changed to Automatic simply because a backup failed.

1. Press Windows key + R.
2. Type services.msc and select OK.
3. Find these services:
   • Volume Shadow Copy
   • Microsoft Software Shadow Copy Provider
4. Double-click Volume Shadow Copy and review its status.
5. If it is running and no backup is active, select Stop, wait for the service to stop, then select Start.
6. Repeat only if necessary for Microsoft Software Shadow Copy Provider.

Warning: Do not stop these services while a backup, restore, system update, disk operation, or application snapshot is running. Stopping a service during a VSS operation can cause that operation to fail.

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Return to the elevated Command Prompt and run:

vssadmin list writers

If every writer is now stable with no error, retry the backup once.

If a particular writer remains failed after a restart, the fix usually belongs to the application or service that owns that writer. For example, a database or business application can install its own VSS writer. Close or restart that application using its documented procedure, then check writer status again. Do not delete VSS registry keys, unregister DLL files, or use scripts that re-register VSS components as a first-line repair; those changes are not needed for ordinary writer failures and can make diagnosis harder.

Repair Windows components only when VSS errors persist​

Use this stage when VSS services cannot start, VSS writers remain unavailable after a restart, or Windows reports damaged system components. These commands require an internet connection if Windows needs to obtain repair files through Windows Update.

1. Open Command Prompt as administrator.
2. Run:

DISM.exe /Online /Cleanup-image /Restorehealth

1. Wait for the command to finish. Do not close the window while it is running.
2. Then run:

sfc /scannow

1. Restart Windows when both commands have finished.
2. Run vssadmin list writers again, then retry the backup.

Expected result: DISM reports that the restore operation completed successfully, and SFC either finds no integrity violations or reports that it repaired files.

Verify that the backup has actually completed​

A successful progress bar is not enough. Confirm that a usable backup was written.

1. Open the backup tool that failed originally.
2. Check its history, status, or last-run time.
3. Confirm the run is marked Completed, Successful, or equivalent—not merely “started” or “partially completed.”
4. Open the destination drive in File Explorer and confirm its free-space figure changed as expected.
5. For File History, open a backed-up folder, right-click a file or folder, select Restore previous versions, and confirm that at least one recent version is available.
6. For a third-party backup or system-image product, use its built-in verify, browse, mount, or restore-test feature if provided. Restore a small noncritical file to a different folder rather than overwriting the original.

If the backup still fails, use Event Viewer to collect the evidence needed to isolate it:

1. Right-click Start and select Event Viewer.
2. Expand Windows Logs.
3. Review Application and System entries at the time the backup failed.
4. Look for entries whose source is VSS, VolSnap, Disk, Ntfs, or the name of the backup application.
5. Match the event time and message to the backup log.

A failure tied to Disk, Ntfs, or repeated device disconnects should be treated as a storage problem. A failure tied to one named VSS writer should be handled as an application-writer problem. If all writers are stable, the destination is healthy, and the backup program alone continues to fail, update or repair that backup product according to its vendor’s instructions rather than changing Windows service defaults.