Spare parts and connections tend to be hard to get a hold of
The large casing does not allow for good dissipation of any heat build up
Desktops are very portable
Desktops tend to have a faster processor for a given price as compared with laptops
Since they are portable, they are not easy to steal
They have very long battery lives
They have many trailing wires
Heat dissipation is more difficult due to the structure of the laptop computers.