Version 10.5.1 was released around 2012 and is optimized for older Windows environments.
. Technical reports indicate the file may perform evasive actions, such as: Hybrid Analysis Virtual Machine Detection Production Suite Scanner 10.5.1 Download
you are currently on 10.5.0 and experience memory leaks, or if you need the new /skip-network flag. Otherwise, no urgent need to upgrade from 10.4.x. Version 10