Clear/Reset the CMOS/BIOS using the jumper according to the user manual description of the procedure. Then enter BIOS, return all BIOS options to your preference, then Save and Exit. Check that the jumper is not left in the clear/reset position.
If running Windows XP, disable HPET (High Performance Event Timer) in System BIOS. XP doesn't support it, anyway. Alternatively, if already disabled, then try enabling it.
Also enable ACPI and APIC in BIOS if not already (though this may necessitate a re-install of the OS).