Popping noise during bootup, then USB mouse goes out!

I recently built myself a new computer, however when I startup the computer I always hear a popping noise over my speakers during the Windows loading screen. When this happens the mouse will flicker and then go out completly. Once windows is fully loaded I am able to unplug and then replug the mouse and everything works fine. However, generaly when this happens the computer becomes very unstable and has sent me to a blue screen and then restart itsself on numerous occations.

One thing I have noticed is the only time this dosnt happen is when I just restart Windows. If its just a restart there is no popping noise and the mouse stays on. It only seems to do it after the system has been completly shut down.

Another thing that I have just recently discovered is that if I go into bios and disable the onboard sound it all seems to go back to normal as well. What could be causing this?

Also the system will run perfectly stable if I can get past the initial loading of Windows.

My specs are as followed...

Gigabyte GA-M55SLI-S4 AM2
Athlon 64 3800+ AM2
2 gigs of Patriot DDR2 667
EVGA Geforce 7600GT PCI-E
WD 250GB Caviar SE16
Enermax 430 watt PSU.

 

Ok, just when I thought I had it figured out... I had disabled the onboard sound and so far that has solved the mouse issue but the system just restarted itsself for no apparent reason!! I just don't get it. It goes to a blue screen but it reboots itself to quick to even get your eyes focused on what the blue screen says.