How to find SQL Server installation Date

To find the installation date of SQL Server, we need to examine the creation date of the "NT Authority\\System" login. This login is created during the SQL Server installation process.

-- Query to retrieve the server installation date
SELECT create_date 
FROM sys.server_principals 
WHERE name = 'NT AUTHORITY\\SYSTEM';

-- Alternate query to retrieve the server installation date using SID
SELECT create_date, *  
FROM sys.server_principals 
WHERE sid = 0x010100000000000512000000;

-- Query to retrieve the creation date for the "NT AUTHORITY\\NETWORK SERVICE" login
SELECT create_date 
FROM sys.server_principals 
WHERE name = N'NT AUTHORITY\\NETWORK SERVICE';

For more information, check out the following articles:

• Server Roles & Permissions
• SQL Server OS Information