It's OK, don't worry about it

Oh, so you just move hard drive from one computer to another without reinstalling Windows?
If that's the case, it won't work.

yes .
how will it work ?

Windows installation is tied up to the hardware on a computer it was installed on, so if you want to move hard drive to another computer, you have to reinstall Windows.

can you please give me some instructions on
installing the windows but i think
i dont have the disk of that
and i dont have money to purchase one .

You'll need some Windows CD. There is no other legal way around.
Why was the hard drive replaced?
What's wrong with the 2nd computer.
Did the computer in question come with any disks?

because the original hard disk of this CPU
is only 40GB and this CPU is faster than the other
and the other CPU is 80GB and slower than
the one i use .
so that i exchange their hard disks.

nothing only the multimedia audio controller
and others work properly.

This is very, very strange, but if you say so....

Install this chipset driver first: VIA Arena - Display Drivers
Restart computer afterwards, and check Device Manager.

okaay sir lemme try this
ill keep online this time
ill be posting here after the
installation . just keep in touch
hehe

sir still no sounds
and still there is a "!" at the realtek AC'97 audio
in the device manager

do you have yahoo messenger ?
for faster communication
you can add me thugcrips21@yahoo.com
thaanks .

Try VIA AC97 driver from here: VIA Arena - Drivers Section
There are 4 listed there, but I can't see one which supports your VT8377 Apollo KT400 chipset.
They're all designed for KT400, so one of them may work.