I found this 'D3Prefs.txt' file in a folder called 'Diablo III' which had appeared in the 'My Documents' folder.
I assumed this file was created during installation or something so I deleted it and the folder it appeared in.
The next time I started Diablo III my graphics settings had reverted to some sort of basic setting and after I had reset my preferences for resolution etc I found that once again I had this folder and file in 'My Documents'.
I use the 'My Documents' folder for immediate downloads if necessary, and any files downloaded there are then moved to a proper folder, I don't like this folder filling up with random rubbish.
What I would like to know is, why is this file clogging up the 'My Documents' folder and not in the 'Program Files/Diablo III' folder where it should be?
Is there any way to get Diablo III to look for this file elsewhere?