UPDATE 18 May 2010:
I came across File Scavenger, a data recovery tool, and it has found all of my missing files. As I type this I am copying all of those ‘lost’ files across to another drive. Phew!
I have two usb external portable drives for my laptop – one ("redpassport") contains pictures, fonts, ephemera. The other ("business") contains all of my business files and until yesterday was ‘seen’ correctly by windows 7.
Now, however, the business drive is named "redpassport" (even when the ‘real’ redpassport is connected to my laptop) and the directory structure windows sees is the one corresponding to my redpassport. Windows cannot see the real structure, nor seemingly rebuild it, offering me only a ‘format disk’ as a way of fixing it (not a solution).
The amount of space available on "business" is correct, only the directory structure and folder names are incorrect.
I have tried connecting the "business" drive to another windows 7 machine and it similarly sees the ‘wrong’ top-level folders, and attempting to drill down from a top level folder only brings a ‘corrupt’ error message.
I downloaded and used xplorer2 to see if it was just a Windows Explorer ‘feature’ but alas xplorer2 shows a similarly incorrect folder structure.
No amount of reboots seem to solve the problem, either.
Your help in rebuilding my file structure most assuredly needed.