Opportunity updates

I have a system that is just implementing opportunties. All the settings seem to be set correctly. When we create an opportunity and start the workflow, they can't make changes to any of the fields in the progress box. They have rights to make edits in security. The only User who can change any of those fields is the system administrator. Seems like a simple setting needs to be changed and I can't seem to find what it is. Anyone have a clue?