Toshiba A300 CPU temp problem

[TomyOne]

Hello,

I got one problem on my 5 years old laptop Toshiba Satelilte A300 (PSAG4E), When processor is on max frequency 2,1GHz, It's starting to overheating, my normal temperature is around 80 - 90 °C and at overheating it goes above 90 °C and when it reach 95 °C laptop is shutdowned.
When I underclock cpu to 2 GHz from Operation system, CPU Temperature is under 90 °C.

I want to set up max working cpu frequency in bios to work max 2 GHz. Is it possible ?
Thx

My BIOS is:

BIOS Type: Phoenix
BIOS Date: January 14th, 2009
BIOS ID: V2.80
BIOS OEM: V2.80
Chipset: Athlon 1100 rev 0
SuperIO: Unknown
Manufacturer: TOSHIBA
Motherboard: Satellite A300D