The main disadvantages of computers are :
1. NULL IQ
2. Dependency
3. Environment
4. Feeling Less
Computer is a dumb machine and it cannot do any work without instruction from the user. It performs the instructions at tremendous speed and with accuracy. It is you to decide what you want to do and in what sequence. So a computer cannot take its own decision as you can.
It can do a task only if it can be expressed in a series of finite steps leading to the completion of the task. It does not have intuition. It cannot draw a conclusion without going through all intermediate steps.
it cannot handle a situation where a finite number of steps generate an impossibly large number of computational operations. It cannot learn from experience. It will commit the same error repeatedly and cannot learn from experience. But changes are taking place in this areaas research progresses on artificial intelligence.
It does not have feelings or emotion, taste, knowledge and experience. Thus it does not get tired even after long hours of work. It does not distinguish between users.