Event 17058 - initerrlog: Could not open error log file (SQL Server)
I face the same problem after windows update on our server. Resolved with these steps.


rename or delete ERRORLOG file found in below directory 


c:\Program Files (x86)\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\Log    


start service


I think the file corrupted. When I change the name, it created a new file.