It's only 1 colon: imagewin:/
Thanks for replying,
I did try 1 colon in "imagewin:/" & Substitute (IMAGELINK ; "" ; "" ) and it turned out the same result. I even used direct calculation imagewin:/C:/IMG_XXXX and FM still could not find the image.
That looks like you should have a folder or two after C: that enclose the file. It's unusual to locate files at that level. You usually want at least one folder after the drive letter. The path's not illegal mind you, just unusual--which makes me wonder if that's really the correct path.
In a calculation field, also make sure that the return type is Container.