Upgrading gcc 3.5 to gcc 4.0

["Chandan M. C." <chandanmc@cdac.in>]

Hai all , 
  I want to Upgrade my kernel to 2.6 and gcc to 3.4 from 3.5 .. Can any
onw help me out How I can upgrade ... 
   I tried installing gcc (cpp3.4,gcc-3.4 and gcc-3.4-base) , Installation
was successful , but it is not changin to gcc4.0 , It is wokring with
previous version gcc3.5 only .... 
   I upgraded kernel too .. But while booting in one stage its giving fcsk
failed , press ctrl+d to continue ... 

Please let me know what packages to be installed to upgrade a kernel .... 


Regards
Chandan