About one year ago i came to the UK with my computer split into its components, each of them in their particular box that it was delivered with, and my two internal HDD's in a separate gpu box, all of them in the hand luggage. I couldn't take the computer case with me, which is why i only took the components.
Now i have to return to my country (in the euro zone) and would like to do the same thing, but i was wondering if the contents of my internal HDD's are going to get checked at the airport?