I have just experienced a problem with my ADC-16. I set it up on a desk top PC and it works fine. However when I transfered it to a laptop with the same operating system, XP, it could not see it. However when I disconnected the instrumentation, the software found it. As soon as I reconnected the instrumentation it could not find the data logger again. The instrumentation is a set of 4 strain gauges in a full bridge. I'm using the adc-16 to power it. Is there a problem with this and do I need to use an external power supply?