WinXP Home not restarting....

Clean install of WinXP Home SP2. Even during the install of XP, there are several reboots required, and this PC will shut down, but won't restart. It stays powered on, but does not actually reboot, and the screen stays black. If I hit the reset button, then all is well. I have messed around with various BIOS settings to no avail. I thought maybe it was a driver issue (I've seen similar behavior caused by faulty or missing sound drivers and/or USB drivers). But even after installing all the system drivers, still no successful reboot. It's an older ECS motherboard, 761GX-M754.
:confused

Thanks!

[dlb]

EDIT- on the topic of the sound drivers: all the Windows sounds work, but if I click the little speaker down by the clock and repeatedly click the volume slider, it should beep with each click, but it doesn't; there's considerable lag between each beep. Even when I stop clicking and go to something else, the beeps continue until the clicks are 'used up'.

 

OK- the sound issue has been solved. Disabling the onboard chip and installing a PnP sound card worked fine. But that was the least of problems. I also tested the CMOS battery which was only reading .62v!!! Strange there were no "battery low" warnings. So a new battery went in, but this may be a sign of a deeper hardware problem.....