I need to edit a file to have people agree to terms before signing up as registered or other user

I thought you had built in a Terms of Use document that had to be approved before a person could sign up. somehow I am afraid that I may have disabled that? I need to be able to edit a document which I would also love to have available on the site, about the terms of use. Can you point me to the setting to turn this on or off and also the location of the file for editing?

Or, let me know what you suggest for this. I must have goofed as I am sure you have this! :-)

Sean Carney