turbo-boost for intel i7 not working in my dell studio 1558

You may need a newer kernel to take advantage of the newer features in the CPU. It may not be supported in the current kernel but there is a PPA with a newer kernel which may help
http://kernel.ubuntu.com/~kernel-ppa/mainline/

They are unofficial and unsupported but may make your CPU work, use at your own risk.

but how to install the kernel and which one to install?

What is the output of:

lsb_release -a

Thanks

No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 10.10
Release: 10.10
Codename: maverick

sudo add-apt-repository ppa:ricotz/unstable; sudo apt-get update; sudo apt-get -y upgrade

sorry, wong post. what is the output of:

uname -a

Thanks

Linux jaguar-Studio-1558 2.6.35-22-generic #35-Ubuntu SMP Sat Oct 16 20:45:36 UTC 2010 x86_64 GNU/Linux

ok so it's 64bit maverick.

cd ~/; mkdir kern; cd kern; wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.37-rc2-maverick/linux-headers-2.6.37-020637rc2-generic_2.6.37-020637rc2.201011160905_amd64.deb && wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.37-rc2-maverick/linux-headers-2.6.37-020637rc2_2.6.37-020637rc2.201011160905_all.deb && wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.37-rc2-maverick/linux-image-2.6.37-020637rc2-generic_2.6.37-020637rc2.201011160905_amd64.deb && sudo dpkg -i *.deb

Should do it. The kernel is not supoprted on here or in #ubuntu but we CAN tell you how to install it. If you get issues, hold down shift, select the original kernel and remove the kernel you just installed