Well i simply used the rm command and removed the VoodooHDA.kext from single user boot command and i don't know it started working.Posting my screenshot of fully working 10.6.4 OS. Thanks a load , just need a small help from you because i dont want to create another thread for that.Currently i am not having any sound and another thing is when i reply and press enter in YAHOO MESSENGER chat box ,it hangs for second and deliver the message.It happened in last reinstalls too and i tried removing and reinstalling it again.Is there any way to fix it.