rapid is a windows service. the only thing that could stop this from being enabled is an antivirus program, a virus, or you're not an "admin" on that windows install.
try installing it with your antivirus turned off.
if that doesn't work do a virus check on your system using malwarebytes, adwcleaner and roguekiller. if your system is clean, make sure you have proper admin access
if everything is good then i'd reboot your pc. uninstall the samsung magician and reinstall it. i had a sorta similar issue with turning rapid off (I couldn't). i had to uninstall the samsung magician and reinstall it to fix that issue.