How to fix Error 5593 on Windows Server 2025 / Windows 11

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Why This Error Happens

Error 5593 occurs because FILESTREAM relies on native 64-bit system calls to manage BLOB data directly on the NTFS/ReFS file system, and these calls are incompatible with the WoW64 (Windows 32-bit on Windows 64-bit) emulation layer. This typically happens when a 32-bit instance of SQL Server 2025 is installed or run on a 64-bit edition of Windows Server 2025 or Windows 11. Since FILESTREAM requires direct, unemulated access to the OS kernel for file I/O operations, SQL Server automatically disables the feature to prevent data corruption or access violations.

Step-by-Step Resolution Guide

Step 1: Verify Your SQL Server Architecture

  • Open SQL Server Management Studio (SSMS) and run SELECT @@VERSION;.
  • Check the output string for “x86” (indicates 32-bit) versus “x64” (indicates 64-bit).
  • If the result shows 32-bit, this confirms the WoW64 compatibility conflict causing Error 5593.

Step 2: Uninstall the 32-bit Instance

  • Navigate to Control Panel > Programs > Programs and Features.
  • Locate the 32-bit SQL Server 2025 instance (it will often be labeled explicitly or found in the C:\Program Files (x86)\Microsoft SQL Server\ directory).
  • Fully uninstall this instance to clear the WoW64 emulation conflict before reinstalling.

Step 3: Install the 64-bit SQL Server 2025 Instance

  • Download the standard (non-x86) installation media from the Microsoft Volume Licensing Center or official SQL Server portal.
  • Run the setup wizard and ensure the installation path defaults to C:\Program Files\Microsoft SQL Server\ (not the (x86) directory).
  • During the Database Engine Configuration step, select the FILESTREAM tab and check the boxes for “Enable FILESTREAM for Transact-SQL access” and “Enable FILESTREAM for file I/O streaming access.”

Step 4: Enable FILESTREAM via SQL Server Configuration Manager

  • Open SQL Server Configuration Manager (sqlserverManager16.msc or relevant version number for 2025).
  • Select SQL Server Services, right-click your instance, and choose Properties.
  • Go to the FILESTREAM tab and ensure “Enable FILESTREAM for Transact-SQL access” is checked, then click Apply.

Alternative or Verification Steps

  • To verify the fix, run EXEC sp_configure 'filestream access level'; in a new query window. A result value of 1 or 2 (rather than 0) confirms the feature is active and no longer blocked by WoW64.
  • If the error persists after reinstalling the 64-bit version, check the Windows Event Viewer under Applications and Services Logs > MSSQLSERVER to ensure no remnants of the old 32-bit registry keys (under HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Microsoft SQL Server) are conflicting with the new instance.