RMS will run with any user rights assigned. However, all users that run POS require read/write access to an area of the registry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Retail Management System\
Or if 64 bit
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Retail Management System\
If you decide to create limited users who need to run POS, you will need to add read/write (full control) access to those users. Log into Windows with admin rights, run regedit, then locate the key above, right-click on it, and select Permissions. Make sure all users listed who will run POS have read/write access to the RMS folder.
The same rule applies to DRS Add-ins for RMS (Local Machine, Software, DRS). Also include any WOW6432Node folder entries if 64 bit PCs. The WOW6432 folder is active for 32 bit applications on 64 bit PCs.
EMV device users: Include Retail Realm folder.
IMPORTANT: You must also install RMS and add-ins initially while logged into Window as a user with admin rights so that registry entries are properly installed.