Please don't comment unless you know what you are talking about as obviously you are worrying him a bit. Anyways wires look fine. Do you got any Model number for the PC??
Well then get in a better reception :/. Try finding a Model number of some sort it should be on the sides of the computer case .
How do I sign in when it keeps not signing me in and saying u can not be signed in at this time please check your mobile network
So I know what is wrong with your model of PC. Due to you having a Prebuilt it is the most likely cause that other Computers have the same issue you are having. I have ideas of what the probable cause is but I like to be sure without making any assumptions.