I did an article a little while ago on installing the Vault 2012 Add-ins for AutoCAD LT 2012 and Inventor LT 2012. There were quite a few steps which made deployment really tricky!
Great News is that the Vault Add-ins are now included in the Vault Client 2013 installation media and the install is really simple.
Remember to install Inventor LT 2013 and/or AutoCAD LT 2013 FIRST and then follow it with the Vault Client 2013 installation.The
The Inventor LT 2013 and AutoCAD LT 2013 Vault Add-ins are only available with Vault Workgroup, Vault Collaboration and Vault Professional 2013.