Bought a laptop Acer Asripe 5542G. A month ago, is the cleaning service center. His the processor AMD Turion (tm) II Ultra Dual-Core Mobile M620. The system is heated and turns off when the core temperature reaches 90 degrees. In the BIOS is not possible to reduce the frequency, and the software to reduce the frequency tools not work. Help me, need reduce the maximum rate from 2500 to 1600.