Sometimes a bad configuration value can prevent SQL Server from starting. Then it won't even let you connect to SQL Server using Enterprise Manager and correct the configuration values. The only option is to start SQL Server in a minimum configuration mode and then correct the configuration values and restart the SQL Server in normal mode. Here's how you can start the SQL Server in a minimal configuration mode :- a) From Command Prompt :- » sqlservr -f b) From Startup Options :- » Go to SQL Server Properties by right-clicking on the Server name in the Enterprise manager. » Under the 'General' tab, click on 'Startup Parameters'. » Enter a value of -f in the Parameter. c) From Registry :- » Go to HKEY_LOCAL_MACHINE\Software\Microsoft\MSSQLServer\MSSQLServer\Parameters. » Add new string value. » Specify the 'Name' as SQLArg(n) & 'Data' as -f. Where n is the argument number in the list of arguments. Caution: Be careful while editing the Registry. Incorrectly setting up Registry values can cause unpredictable behavior.