These informational files are generated to locate any problems during setup.
The Sqlstp.log file, located in your \Windows or \WinNT directory. For example, C:\WinNT\Sqlstp.log.Any errors encountered during the configuration portion of setup are written to this file.
The Setup.log file, located in your \Windows or \WinNT directory. For example, C:\WinNT\Setup.log.
The most recent error log, located in the \Log directory of the target installation directory. For example, the default location for the error log is C:\Program Files\Microsoft SQL Server\Mssql\Log\Errorlog. For a named instance, the error log would be in \Microsoft SQL Server\Mssql$<instancename>\Log\Errorlog.