You don’t need administrator permissions.
Once you install Anaconda or Miniconda on Windows, open a Anaconda PowerShell Prompt from Start Menu.
Or, if you don’t see it there, then assuming you have installed
miniconda3 at path C:\miniconda3\4.9.2, do:
powershell -ExecutionPolicy ByPass -NoExit -Command "& 'C:\miniconda3\4.9.2\shell\condabin\conda-hook.ps1' ; conda activate 'C:\miniconda3\4.9.2' "
Now try:
conda init powershell
and reopen PowerShell.
Additional note: By default, conda will autoactivate itself, when we open terminal. If you prefer not, then disable auto-activation with:
conda config --set auto_activate_base false