To be helpful, we need to know more about your computer and connection. Brand, model, hard drive, memory, power supply, age, connection.
Computers can freeze from setup, spyware, defective memory, defective video graphics, defective or outdated drivers, power supplies or power adapters, dust or dirt or fiber in cooling channels or cpu fan, and a number of software install defects... so please tell us enough to give you some good speculation.