Perhaps the log is on is a network share that is only visible to the SQL Server service account?
If this were the case you could log onto the server using that same service account used by SQL Server, and "see" the drive in Windows Explorer.
SQL Server will refuse to load a database if it cannot locate a valid log file. It will NOT simply create the log file in the "default" Log file location.
An alternate method to see if the log file really exists, and perhaps where it actually is, would be to use the
xp_cmdshell extended stored procedure to run a
dir command on the SQL Server itself, in the context of the service account. This relies on having
exec sp_configure 'xp_cmdshell' being set to
xp_cmdshell is enabled, you could run the following:
EXEC xp_cmdshell 'DIR C:\temp\*.ldf'; --replace with the path to the log file in question
EXEC xp_cmdshell 'net use'; -- this shows the mapped network drives SQL Server can "see"