front page category button sizes...

[moobi]

hi all.
if you look at techberry.co.uk you see the sample stuff installed as standard and i have it set up to show category images on the front page. but do you know how to change the size of the category images as they are a bit small on that page, e.g. when i upload products a category image might be a laptop but at the moment the picture looks small, so what file do i edit to make it a bit bigger?

Thanks

[gjh42]

Admin > Configuration > Images.
There are two "subcategory" entries - try them and see which one does what you want.