SQL server service could not be started: Error: "The Request Failed Or The Service Did Not Respond In A Timely Fashion. Consult The Event Log Or Other Applicable Error Logs For Details Error When Starting SQL Server Instance"
Please check if the customer has a copy of backup for the DB
Open Windows Explorer and go to the folder C:\Program Files\Microsoft SQL Server\MSSQL10_50.\MSSQL. If you are not running the instance of SQL Server, the MSSQL10.It may have a different name.
Rename the folder "DATA." You can simply rename it "DATA.old."
Create a new folder in this directory named "DATA."
Open the "Template Data" folder and copy all of the files in this directory.
Paste the copy of these files into the newly created C:\Program Files\Microsoft SQL Server\MSSQL10_50.\MSSQL\DATA folder.
Go to SQL Server Configuration Manager and try to start the SQL Server Service again, it should start now.
Test your application to confirm it now works.
It it still doesn't work-
Open SQL Server Configuration manager
Click on the SQL Server Services (on the left)
Double-click on the SQL Server Instance that I wanted to start
Select the Built-in account radio button in the Log On tab and choose Local system from the dropdown menu
Click apply at the bottom, then right click the instance and select Start