Hello benegin,
The problem you are describing is typical of either a hardware conflict or corrupt driver. Perhaps when you installed you new hard drive (and reinstalled all your drivers/hardware) you received conflicting devices.
You mentioned that this one application causes your computer to crash. Does your computer reboot/crash when running any other application, or any other VI inside LabVIEW? If other LabVIEW programs cause your computer to crash do they require NI-DAQ VIs, or does it seem to be more related to LabVIEW instead of your DAQ device? For example you mention that you use a timed loop and file I/O. If you just use a timed loop or just do file I/O in a VI does this cause your computer to reboot? If the reboot is related to your DAQ device, can you cause the same crash when just using Measurement and Automation Explorer (MAX) test panels?
If you believe the problem is related to your devices (or drivers), you can try upgrading your version of the DAQ driver. You can find the newest driver for WinXP/2000
here that works with LabVIEW 6.0.
Regards,
Jesse O.
Applications Engineering
National Instruments
Jesse O. | National Instruments R&D