Using "RStudio-2026.09.0-174.exe" /S no longer silently installs for all users. Installer's help "/?" still shows /S as a valid switch any other suggestions?
You could try running the installer with elevated administrator privileges and checking whether the newer installer has changed its silent install behavior. It may also be worth testing /S from an elevated command prompt and reviewing the installer logs for any errors. If /S is still accepted but no longer installed for all users, there may have been a change in the installer configuration rather than the switch itself.
New switches of /allusers /S installs properly for me. New uninstall switches of /uninstall /allusers /S works for me.