You can edit the greeting page and remove the text for link which will remove it from plain sight on your TeamRaiser home page.
  1. Fundraising > TeamRaiser.
  2. Select edit next to the event.
  3. Select Step 13. Customize Pages.
  4. Select Configure next to Greeting.
  5. Scroll down to the Register as an Individual section and remove the value in the "Text for Link"  box.
  6. Save your changes.