conda update conda not working due to Windows Program Files permissions

Go to the start manual, find Anaconda Command Prompt. Right click on the icon and run it as an administrator (if you are). Then do the conda update as usual.

Ok so I installed Anaconda for myself only (instead of all users) and this solved the problem. Conversely, you can install Anaconda for all users and change the installation directory from 'Program Files' to your home directory and that should work. Quite a pain.