How to fix Error 3264 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 3264 – “RESTART Qualifier” Failure

Why This Error Happens

Error 3264 occurs when a RESTORE command is issued with the WITH RESTART option, but SQL Server cannot find a valid checkpoint from a previously interrupted restore operation to resume from. This typically happens because the prior restore was cancelled too early (before SQL Server wrote an internal restart checkpoint to msdb), the restore operation actually completed successfully before being reissued, or the msdb restart history was cleared/corrupted between attempts. Essentially, SQL Server 2025 has no “bookmark” to pick up from, making the RESTART qualifier invalid for that specific restore sequence.

Step-by-Step Resolution Guide

Step 1: Reissue the Restore Without the RESTART Qualifier

  • Open SQL Server Management Studio (SSMS) or your query tool connected to the Windows Server 2025 / Windows 11 instance.
  • Remove WITH RESTART from your T-SQL statement and run the restore from the beginning:
  • RESTORE DATABASE [YourDB] FROM DISK = N'C:\Backups\YourDB.bak' WITH REPLACE, STATS = 5;
  • This forces a fresh, full restore pass instead of attempting to resume a nonexistent checkpoint.

Step 2: Verify the Backup File Integrity

  • Confirm the .bak file is not truncated, corrupted, or still locked by another process (check Task Manager for lingering sqlservr.exe handles).
  • Run a verification check before restoring:
  • RESTORE VERIFYONLY FROM DISK = N'C:\Backups\YourDB.bak';
  • If verification fails, obtain a fresh backup copy from the source system or backup repository.

Step 3: Check and Clear Stale Restore History in msdb

  • Query the msdb.dbo.restorehistory table to confirm whether a valid restart checkpoint actually exists for this database.
  • SELECT * FROM msdb.dbo.restorehistory WHERE destination_database_name = 'YourDB' ORDER BY restore_date DESC;
  • If no valid incomplete entry is found (or the last entry shows a completed restore), this confirms RESTART has no valid state to resume — proceed with a full restore instead.

Step 4: Confirm Sufficient Disk Space and Permissions

  • Ensure the SQL Server service account has read/write access to both the backup source folder and the target data/log file directories (commonly C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\DATA\).
  • Check available disk space on the drive hosting the .mdf/.ldf files — insufficient space can cause the restore to silently abort before writing a restart checkpoint, triggering this error on retry.
  • Use File Explorer or PowerShell (Get-PSDrive) to confirm free space exceeds the backup file size by at least 1.5x.

Alternative or Verification Steps

  • After reissuing the restore without RESTART, monitor progress via SELECT percent_complete, estimated_completion_time FROM sys.dm_exec_requests WHERE command = 'RESTORE DATABASE'; to confirm it completes without aborting.
  • If the issue persists across multiple attempts, use WITH NORECOVERY to break the restore into separate full/differential/log steps, which avoids RESTART dependency entirely for staged restore sequences.