Generally, laptops use slower hard drives, 4200rpm, and have slower system busses. This is to conserve battery power. The CPU may be running at the same clock speed as a desktop, but it will not perform the same. In general, a laptop at "X" speed will be slower than a desktop at same "X" speed.
Your laptop may run the satellite box, but if it is an older laptop, the USB port will not be USB 2. Check the requirements of the satelllite box. If it does run, it will probably need to be tweeked for maximum performance, picking the best drivers requiring the least CPU power for the decoding.