I hit the EXEC sp_configure 'show advanced options', 1; But the "backup checksum default" is not showing
If you are sysadmin on the SQL Server instance, then you can run the following script to see which options are available:

SELECT [name] FROM sys.configurations


This will give you the following possible setting on a SQL Server 2012 instance:

configuration_id name
---------------- -----------------------------------
101              recovery interval (min)
102              allow updates
103              user connections
106              locks
107              open objects
109              fill factor (%)
114              disallow results from triggers
115              nested triggers
116              server trigger recursion
117              remote access
124              default language
400              cross db ownership chaining
503              max worker threads
505              network packet size (B)
518              show advanced options
542              remote proc trans
544              c2 audit mode
1126             default full-text language
1127             two digit year cutoff
1505             index create memory (KB)
1517             priority boost
1519             remote login timeout (s)
1520             remote query timeout (s)
1531             cursor threshold
1532             set working set size
1534             user options
1535             affinity mask
1536             max text repl size (B)
1537             media retention
1538             cost threshold for parallelism
1539             max degree of parallelism
1540             min memory per query (KB)
1541             query wait (s)
1543             min server memory (MB)
1544             max server memory (MB)
1545             query governor cost limit
1546             lightweight pooling
1547             scan for startup procs
1549             affinity64 mask
1550             affinity I/O mask
1551             affinity64 I/O mask
1555             transform noise words
1556             precompute rank
1557             PH timeout (s)
1562             clr enabled
1563             max full-text crawl range
1564             ft notify bandwidth (min)
1565             ft notify bandwidth (max)
1566             ft crawl bandwidth (min)
1567             ft crawl bandwidth (max)
1568             default trace enabled
1569             blocked process threshold (s)
1570             in-doubt xact resolution
1576             remote admin connections
1577             common criteria compliance enabled
1578             EKM provider enabled
1579             backup compression default
1580             filestream access level
1581             optimize for ad hoc workloads
1582             access check cache bucket count
1583             access check cache quota
16384            Agent XPs
16386            Database Mail XPs
16387            SMO and DMO XPs
16388            Ole Automation Procedures
16390            xp_cmdshell
16391            Ad Hoc Distributed Queries
16392            Replication XPs
16393            contained database authentication



  WARNING: Please do NOT change configuration settings in the table directly. Always use sp_configure &lt;option&gt; &lt;value&gt; to modify the instance.


Or you could read up on the configuration options on Technet:  

Server Configuration Options (SQL Server 2012)