Turning off dell support assist in the BIOS....

first you need to disable the hook at boot that calls the process or it will keep initiating a call  and changing the setting in bios as soon as you reboot

Caution the following setting changes are to be used with caution - these configurations are making changes in the software and may effect the performance of correlating applications 

ms config Find the service that correlates with the software and disable

check your system services ( admin cmd prompt services.msc enter ) find the correlating entry to the  software right click entry  select properties and disable the service 

save and close  all programs and  shut down system

make your changes in BIOS and be sure to select apply or choose the appropriate prompt for saving reboot system

this should solve this problem the manufacturer preinstalled applications may all be working in orchestration and if your managing entity depends on  any of these in integrated service monitoring you should make system admin  aware you are disabling this feature