I have the same error message "Unit not opened" when running ps2000a.xls
My configuration Picoscope 2205A, PicoSDK 10.6.10.22, Windows 7 / 64 bits, Excel 2007 / 32 bits
The 3 necessary dll's are in the right place and I have checked that Picoscope 6 is not running when running Excel macro.
Function ps2000aOpenUnit returns handle=0 and so the error message appears.
How to solve this problem ?