This article applies to the 123-reg InstantSite package.
This article will explain how you can remove messages for your Guestbook on InstantSite
Scroll down to the Create your website section and click on the InstantSite icon.
Click on the Login button next to the relevant InstantSite package.
Click on the Edit link.
In the Site map panel, click on the Guestbook page.
Click the check box against the message that you want to delete.
Click on the Remove Selected button.
Click on the OK button to confirm the removal of the message.