Hi Themos Thanks for the reply - did already the right-mouse click "Open With" and even though I selected the python.exe file by browsing to it and ensuring that I selected it as the "default program" stubbornly it doesn't do it at all and I get back other installed programs in the list except Python!! Done a few other hacks as well as posted by others on the web but to no avail - methinks a "wipe & re-install" is required as I feel that the registry is corrupted somehow. BTW this is what I get when I ran PPA.py in the command shell: C:\Users\Ops\Documents\PhotoPolarAlign>python PPA.pyTraceback (most recent call last): File "PPA.py", line 1501, in <module> APP = PhotoPolarAlign(master=ROOT) File "PPA.py", line 1495, in __init__ self.Sniff_AstroTortilla() File "PPA.py", line 1305, in Sniff_AstroTortilla lfn = os.listdir(dir)WindowsError: [Error 3] The system cannot find the path specified: 'C\\Users\\Ops\\AppData\\Local\\astrotortilla.sf.net\\AstroTortilla/*.*'C:\Users\Ops\Documents\PhotoPolarAlign>HTHCheersBillfrom Sunny & Extremely Hot Perth, DownUnder