I have a new Pico 3205b. I am running VS2008 c++ on Win7-64. It compiles OK and GUI looks OK, but when I select OpenDevice on menu the gHandle= ps3000_open_unit() returns 0. I have plugged and unplugged the CRO and it works OK in the Pico Oscilloscope software. I have 25 years real time programming experience so I admit I don't really understand plug and pray.