Occasionally there are times in which you need to identify which version of NAV you are working with but the actual NAV client is inaccessible. In this situation, if you have access to the SQL database for the NAV instance in question, the following process will help to identify what version of NAV is in use.
In SQL Server Management Studio, open a 'New Query' window. Make sure that the active database selected is set to your NAV database instead of the default 'master'.
Once connected to the appropriate database, paste the following code-block into your SQL query window and execute. This will return a plain-text description of the version of NAV in use, as well as the NAV Database Version number.
WHEN [databaseversionno] = 40 THEN 'Navision 4 SP2'
WHEN [databaseversionno] = 80 THEN 'Navision 5 / 2005'
WHEN [databaseversionno] = 95 THEN 'Navision 5 / 2005 SP1'
WHEN [databaseversionno] BETWEEN 120 AND 60199 THEN 'Navision 6 / 2009'
WHEN [databaseversionno] BETWEEN 60200 AND 70199 THEN 'Navision 6 / 2009 R2'
WHEN [databaseversionno] BETWEEN 70200 AND 70719 THEN 'Navision 7 / 2013'
WHEN [databaseversionno] >= 70720 THEN 'Navision 7 / 2013 R2 (or later)'
END AS [NAV Database Version]
, [databaseversionno] [NAV Database Version No]