> A full path would have a number of folder names in it. Even if the backslashes were being eaten there would be many characters between the 'C:' and the filename. Correct. My comment was based on an earlier comment where it was said that the root drive was being used, hence only needing to have a single unescaped backslash character. Your comment is exactly correct, a fully qualified path needs to be used (I think) to resolve this problem. I was only pointing out that the particular test case was trying to use the root directory, which would not need a long path, and would likely result in a failure to open because of an inability (by default) to create and / or write to the root directory of the C drive in Windows 10.