The current SQL Server error log is a text file. You can view it by using any text editor. The default location of the error log is determined by an entry in the Windows NT Registry from information supplied during setup. The default location is C:\SQL60\LOG\ERRORLOG.
A new error log is created each time SQL Server is started. Typically, SQL Server retains backups of the previous six error logs, giving the most recent log backup the extension .1, the second-most recent the extension .2, and the oldest the extension .6.