Basic Server Info to obtain SQL Version and OS Version.

/*
Basic Info
*/

SELECT
SERVERPROPERTY('ServerName')	 'SQLServerName',
COALESCE(SERVERPROPERTY('InstanceName'),'DEFAULT') 'InstanceName',
SERVERPROPERTY('ProductVersion') 'ProductVersion',
SERVERPROPERTY('ProductLevel')   'ProductLevel',
SERVERPROPERTY('Edition')		 'Edition',
CASE 
WHEN RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.2 then 'Windows 2012'
WHEN RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.1 then 'Windows 2008R2'
WHEN RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 6.0 then 'Windows 2008'
WHEN RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 5.2 then 'Windows 2003'
WHEN RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 5.1 then 'Windows XP'
WHEN RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)= 5.0 then 'Windows 2000'

ELSE RIGHT(SUBSTRING(@@VERSION, CHARINDEX('Windows NT', @@VERSION), 14), 3)
END	'Windows Version'

Example