Need help with overclocking HD 7670M !!!

[Terven3]

Hello everyone, I own a Toshiba Satellite L855 notebook with the following specs:
Intel Core i5 2450m 2.5-3.1 Ghz
AMD Radeon HD 7670M 1GB (with the latest catalyst beta drivers dxdiag says im running the 14.200.0.0 driver)
4GB DDR3 RAM
Win 7 64 bit

My gpu is struggling to get 30 fps with new games,so i decided to try overclocking it

.I tried using MSI afterburner,but every time I adjust the core or memory speed,even slightly, my screen crashes and starts displaying black bars and I often get the message "amd driver has stopped working and recovered".If i put the latop to sleep and open it again , the screen returns to its normal state,but then I experience the following problems:

1) Apps like Fraps,Dxdiag etc crash when i open them(e.g. APPCRASH,stackhash etc)

2)Games crash either when i open them, or at the loading screen even if I only boost the core speed from 600 to 700

I tried overclocking with different amd drivers , old and new , but the problem persists.
If any of you has any idea how to successfully overclock my gpu,please respond . Thanks in advance !!! (NOTE: I know notebook overclocking is risky)

 

[Automata]

Most notebooks are not going to handle overclocking well. They are made to run at a specific max speed. Increasing speeds either draws too much power or the card will give out too much heat. That could be the source of your problems. It is reasonable that programs don't act correctly after the video driver crashes out.

I had a Toshiba Satellite quite a few years ago. I wouldn't even think about overclocking that thing as it didn't run stock most of the time without overheating.

Someone here may have specific information for that laptop.