Additional SQL Server features and topics not covered by specific categories
For SQL Server 2025 installation failures, start with the most common causes supported by the setup errors shown in Microsoft guidance:
- Use fresh installation media.
- Download the SQL Server image again from the original source.
- Corrupted or damaged installation media can cause setup failures such as bad image, corrupt cabinet files, file read errors, and setup package errors.
- Install from a local drive, not a network location.
- If the installer is being run from a shared folder, USB, or other remote location, copy the installation files to a local folder and run
Setup.exethere.
- If the installer is being run from a shared folder, USB, or other remote location, copy the installation files to a local folder and run
- Check the SQL Server setup logs to find the failing component.
- Open the setup Failure screen and select Details.
- Go to
%programfiles%\Microsoft SQL Server\nnn\Setup Bootstrap\Log. - Open
Summary.txtand look under Product features discovered for the feature that failed. - Open the timestamped log folder that matches the failure time.
- Review
Details.txtand search for Failed. - If the Database Engine failed, check the feature-specific log files and the SQL Server
ERRORLOG.
- If the error mentions
Setup.rll, rename that file and rerun setup.- Open File Explorer.
- Go to
C:\Program Files\Microsoft SQL Server\1XX\Setup Bootstrap\SQLXXX\resources\1033. - Rename
Setup.rlltosetup.rll.old. - Run setup again.
- If the installer reports language or localization problems, verify OS language support.
- If using a localized SQL Server version, Windows must support that localized version.
- Different language versions of SQL Server instances on the same computer are not supported.
- If SQL Server 2025 setup fails early, verify TLS 1.2 is enabled.
- SQL Server 2025 installation fails if TLS 1.2 is disabled.
- Warning: incorrectly editing the registry can severely damage the system. Back up important data first.
- The relevant registry path is:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols
- If the machine is Windows Arm64, SQL Server 2025 is not supported.
- SQL Server 2025 supports Intel and AMD x86-64 CPUs, not Windows Arm64.
- If setup reaches Database Engine startup and fails with
Wait on the Database Engine recovery handle failed, inspect the SQL ServerERRORLOG.- For SQL Server 2025, check the instance log under the SQL Server installation path and review the
ERRORLOGfor the exact startup failure. - A reported known scenario is
256 misaligned log IOs, which requires the published workaround for the disk sector size issue.
- For SQL Server 2025, check the instance log under the SQL Server installation path and review the
If the exact error text is available from the setup screen or from Summary.txt / Details.txt, the next step is to match it to one of these cases and fix that specific cause.
References: