If you feel you can get a good grade in it without too much effort that would pull down your other subjects, contiune with it, otherwise don't.
From what I know of the subjects you took, ie Maths,Chem,Phys, your time would be far better spent concentrating on doing well in them, instead of ICT lessons.
Most uni's will ask for your grades to be in them 3 I would imagine.
Surprised at warwick being ABB for chemistry, I was convinced that the only courses less then AAB were for languages, and that was probably only due to the shortage of good linguists. Ahh well...