LabTutor uses a modified version of LabChart call the LabTutor Kernel to connect to a PowerLab for data acquisition. If the LabTutor Kernel and/or the LabTutor instance was not closed prior to starting LabChart, LabChart will be unable to connect to the PowerLab because the LabTutor Kernel will still be controlling it. To solve this issue, close the LabTutor instance, turn off the PowerLab, and turn the PowerLab back on. If the green LabTutor Kernel icon still appears in the Windows Systems Tray, left click on the LabTutor Kernel icon and select "Exit LabTutor Kernel". LabChart should now be able to discover and connect to the PowerLab when the software is started.
If you require further technical assistance with this or any other issue, please contact ADInstruments Technical Support.