Flying with a desktop computer (as checked luggage)

I must take George's comment to an answer because it's too important: depending on the kind, the heatsink may need to be removed. Apply common sense / guess the centre of gravity. If it looks like this:

it very likely will cause no problems. If it looks like this:

you definitely do not want that bumping around.

I personally would take some precautions. First of all, make a backup of your data. Leave on in your home and take another one with you so that you can use it in your destination place. Then when transporting a desktop computer, the most fragile part is almost always the hard disk drive. So I would dismount it if possible and take it into your cabin luggage. You could also do this for other sensible parts like for example other drives, the processor, or the RAM bars. This I would pack into anti-static bags and take it into the cabin.

The tower itself you can put into protected pc transporting bags like this one. This bag will be checked so that you can't smuggle and weapons or drugs. But you shouldn't normally fear that this will damage your computer.

And last but not least, you could also think about sending your computer with a carrier. I quote this from a message board:

Send it via a Secured Carrier, RPS(Royal Packaging Service), Which Delivers Things in the most pristine state Possible. Door to door Service, White glove care. But i warn you, Its pricey. 15lb = $200/USD.

I've shipped the kid's gaming computer twice on an airline. Both times it was partially disassembled on arrival. With a huge heatsink for the chip, it must look suspicious to the uninformed at TSA. Had to rebuild it both times. Third time, FedEX - same thing.

Depending on the size of the case and your level of pain tolerance, it may also be possible to take it as carry-on luggage.

I've done that twice now, although with a small flat desktop PC (that is within hand luggage size regulations), and aside from being taken aside at security for explosives screening (which involved me opening the case) and actually carrying the thing around, it was easy enough.

Obviously the safest solution is to not check it -- instead bring it as a carry-on. I've done this. If the computer is within the weight and dimension limits of your carrier for carryon luggage, then there is apparently no reason why you can't bring it with you onboard.

I think I would fill it with packing peanuts and then wrap it in fleece filts, then of course take out the hard drive. I would then pack it into a hard bag and I'll make sure that the desktop has no space to slide around.

I think the best way is just disassemble your PC parts like Motherboard, HDD, Power Supply etc and leave the casing. You can buy new casing and reassemble to that new casing from your new destination country. This is most safest easiest way. Because you no need to worry about parts being not broken or anything during travel.