You are probably seeing a device configuration error. When you remove a device, then install it once again, MAX (Measurement and Automation Explorer) will not "remember" the previous device ID number. I see this problem everytime I remove my PCMCIA card and reinstall it. I have assigned the device to ID number 5. Each time I reinstall it, MAX assigns it the ID of 1. So, I go back into MAX and change the ID number to 5. Then all is well.
I have also had to force MAX to accept the device ID I desire by first, changing the ID to, say 2, then to 5. I would suggest that after booting the computer, you launch MAX and use the "Test Resources" button. If the Device passes the test then you can use the device in LabVIEW. If the device fails the test, change the ID to so
me other number, test it, then change it back to the Device ID you want. It works every time for me.