Sometime due to some technical problems or uncleaned shutdown master database of MSSQL gets corrupted and while starting MSSQL service it throws following Error

Application Log in Event Viewer shows following Error

Cannot recover the master database. SQL Server is unable to run. Restore master from a full backup, repair it, or rebuild it.

The above error shows that the System Database like Master has been corrupted. To fix this issue we need to rebuild the MSSQL system databases from Installation Disk.

1) Insert MSSQL Installation Disk in Optical Disk Drive

2) Go to Command Prompt (Start >> run >> cmd >> Enter)

3) Execute Following Command:

start /wait []\setup.exe /qn INSTANCENAME=[Instance Name] REINSTALL=SQL_Engine REBUILDDATABASE=1 SAPWD=[Password]

Here, [Instance Name] will be the name of the MSSQL instance you want to set like MSSQLSERVER and [Password] will be the sa password for MSSQL.

Now try to start MSSQL service.