This is a somewhat known problem for version 1.x of Nuendo and Windows XP. Try turning off ACPI mode (going to Standard PC mode) and sometimes this helps.

How to disable ACPI mode in Windows XP:

* This step is recommended to be one of the last options to try since it drastically changes your system's IRQ configuration.

Here's how you can switch back to the normal Win98-BIOS-controlled IRQs.

* This step is not recommended for DUAL PROCESSOR machines - disabling ACPI will disable dual-processor support.

* WARNING: YOU MUST HAVE ALL HARDWARE DRIVERS AVAILABLE AT RESTART. This will re-detect ALL your hardware, and any hardware drivers needed will be asked for. THERE IS A (slight) CHANCE THIS WILL RENDER YOUR SYSTEM UNBOOTABLE, do this at your own risk.

* If you have a USB mouse, you may need to find an old PS/2 (round connector) mouse. USB is one of the last devices detected in this process, and therefore your mouse pointer will be unusable for part of this process if it is USB.

To disable ACPI, please change the system setting from 'ACPI-PC' to 'Standard-PC'. Right-Click on My Computer -> Properties -> Hardware -> Device Manager -> Computer -> Advanced Configuration and Power Interface (ACPI) PC -> Driver -> Update Driver -> Install from a list or specific location -> Don't Search.. -> Standard-PC.

Note that changing this means that all drivers of your hardware are re-installed (keep the driver disks available). Additionally, make sure that PNP OS INSTALLED in BIOS is set to NO (very important). Also note that disabling ACPI mode may cause your computer to not power off when you perform a Windows shutdown. Simply push the power button after performing a shutdown.

Reversing this step - re-enabling ACPI - is as simple as repeating this step and choosing ACPI-compliant PC instead of Standard.