There is a service menu on the DTI6300 which allows you to format the hard disk.
The Thomson DTI6300 box has a 'secret' Engineers menu, which can be accessed as follows: Press the Menu button, select Setup, select Help, then enter 1397.
This gives a number of options, including fan speed, box temperature and smart card info. Scrolling down, there are also options for HDD partition check, power mode test, ATAPI reset and force next over-air-download. There seems to be an option to perform a check on the hard-disc, but this wasn't working for us.
To perform a full reset and format of the box. Do the following:
* Menu > Setup > Help
* Then press the Green Button (Even though it doesn't show as an option)
* Then press the Red button for a full reset
Hope this helps
RepairKing, April 2009