Thanks for your help but the code you provided gave me error:
This is a part of the terminal screen I got after typing the download link:
Checked out revision 293.
zohair@ubuntu:~$ cd omnibook
make: *** No targets specified and no makefile found. Stop.
zohair@ubuntu:~/omnibook$ sudo make install
make: *** No rule to make target `install'. Stop.
And mfillpot, thanks for your contribution but I found a similar program "KPowerSave" that seems to similar to what you've suggested.
but to be honest guys the problems is that in addition to my CPU heating, my HDD never stops, it keeps running for ever. Further suggestions are much appreciated.