If you have purchased the full version and after you have entered the serial number it reverts to trial again. It is possible that when you copied the serial number you copied a space or something before or after the password this would definatley make it fail to register. Your best bet is to type it in manually if it keeps happening.
 
Please also make sure you have the latest versions of windows media player, real player and quicktime to avoid problems playing tv channels...
 
This program requires microsoft.net framework 2 installed to function and should download during installation automatically if this does not happen you can manually download and install from microsofts website.
 
if you get - invoking just-in-time(JIT) debugging 
 
just-in-time(JIT) is part of java runtime and usually means you need "JIT 
compiler..." enabled in internet advanced options...approx half way 
down...enable that & restart your computer and all should be ok..

you need to let gogglebox tv have access to internet in your firewall and/or router if you have one.
 
Please also make sure you allow access to the program from within your your firewall / router
 
Thanks..