Build number 18.104.22.168 (17 May 2012).
To update your current build
of NW2010, please download it along with the version history document,
which has the update instructions on page one, from http://nintexdownload.com/sl/supportfiles/NW2010_version_history.pdf
determine which build you have, go to the Workflow Designer, on the
Ribbon, expand the Help menu and click on About Nintex Workflow.
note that due to the inclusion of Nintex Workflow Enterprise Edition
features, you will notice an additional Nintex solution package in the
solutions list. The Enterprise solution package should not be
additionally deployed by users without an Enterprise license as problems
may occur. Standard Edition users should just update Nintex Workflow
2010 as normal.
Additonal note: You will not be able to upgrade without a valid Software Assurance or Premium Support contract in place.
check if you are covered, please go to SharePoint Central
Administration, locate the Nintex Workflow Management section and click
"Licensing". If the Software Assurance or Premium Support expiry date
is in the future, you will be able to upgrade.