'How to mend it' recommend that you state the make and also the model in the question title. You have not done this. This makes it difficult for others to help you. E.g those with a model of XXXX will not know that you are also asking about XXXX.
Once you know which make and model you own a google search may come up with instant fixes. If they do not appear to work the please include a description of your endevours in your question on 'How to mend it'.
This will help repliers undersytand about your own particular problem.
Freeview boxes of the same model can behave very differently depending on the software they are using. Within the menu system there is a screen that will tell you which version of software you are using. How to get to that screen will depend on the make and model of your freeview box Frequently all that is needed is to update this to the latest version. In future questions see if you can locate this software version and quote it as well as the make and model. Stating the make, model and software version will enable responders to advise you if having old software is the issue and also advise on the easiest method to get it updated for your particular make and model.
NS, February 2013