When I compile a LabView 5.1.1 vi program that uses lvdaq.dll on my Windows 2000 workstation, that same program will not run on a Windows 95 notebook computer. Error code 21 (external subroutine could not be found) is reported for all standard DAQ vi's calling functions within lvdaq.dll even though the dll can be found in the program directory, the system directory, the vi.lib\daq directory, and via the system path. The same program compiled on a Windows 95 workstation runs on the Windows 95 notebook computer just fine. Why is lvdaq.dll not found when the program is compiled under Windows 2000? Do I need the same version of NI-DAQ on both computers?