Please get to know Telnet. Details in the Wiki
HERE (click). Telnet is important for fixing things, sometimes even things which don't improve with a re-install.
You will (presuming the CF is up to date) see a prompt for your PIN on connection (the PIN you have set for your Humax - default is "0000"). You will get a menu. Select "cli", and then you get to a command prompt for the Linux console (much like using the cmd console in Windows, or the old MS-DOS command line if you are old enough to remember pre-Windows).
Type "service" and you will get a list of CF services, which should include mongoose. It should be set to "auto", if not type "service auto mongoose" to make it so.