Can I carry a desktop computer case board on aircraft?

I want to inquire that if United Airline and TSA allows passenger to carry one desktop computer case on board the aircraft .





ps:My computer case size 17.2'; x 8.2'; x 18.4';(HxWxD)


Thanks if any helpCan I carry a desktop computer case board on aircraft?
Now why would you want to carry a desktop on board, kind of stupid. I doubt they will let you tho cause of all those things happening.