How hard do you think computer hardware is?  

No, that is very easy. As your said, nothing can be put in the wrong slot. But, ensure you put the jumpers without wrong place. For old computer hardware, many jumper can remove easier. But, only few jumper in new computer hardware that make it seems easier. I am not fear of breaking it, i already breaking it hehe. And, i need to buy new computer hardware to fix my PC.

hello there...

well, my fear before opening the casing of the PC is, i might ruin the computer hardware in the PC... because most of the hardware will not take any resistances from getting damaged... they all like to get damage if we do anything wrong or simple mistake anyway... hehe... well, by simple mistakes i mean like for example, static electricity which you did not properly discharged it, placed the hardware into wrong slot, did not insert or pushed the hardware to its slot properly and much more... if you did not insert the hardware to its place or slot properly, you going have a "very good" system when you turn on your PC... it will just won't turn on... because even to the one of the hardware connection is not properly connected, your systems going to get fried the moment you turn them on... this is because not all hardware are capable of coping such s"illy mistakes" situations... we might know that we did something wrong but the hardware?? of course not... so that is why i got some fear when i want to open the casing of the PC... just make sure that you know what to do before and after opening and closing back the casing for example, discharging static electricity... this will help you to reduce your system before it get fried completely...