I think you may have a dynamic disk
http://technet.microsoft.com/en-gb/library/cc737048(v=ws.10).aspx rather than a normal one. This might mean that you have two drive mappings to the same actual volume. This might or might not be an error - it might simply mean that the space on the real volume will be dynamically shared between the two mapped drives you see.
If your computer is less than three years old, you probably have a GPT disc partition structure, and if in addition you have done some uninformed meddling with some system-level software older than three years, this might be an unintended consequence.
However, I don't really know what I am talking about, and certainly until you know definitively what is going on, you must not use any partition manager to delete drive X:
I think it might be safe to copy a test file from drive C: to drive X: and see what happens. Or save a document to drive X: and see if it also shows up on drive C: root.
Or here is a solution to a similar problem in post#11
https://code.google.com/p/chromium/issues/detail?id=226458
It's possible this problem or similar has occurred - but it's about network mapped drives
http://social.technet.microsoft.com...plicate-mapped-drives?forum=w7itpronetworking
It seems it may be a new windows 8 problem, bug or a virus. Or caused by specific software as here
http://superuser.com/questions/3179...ter-deploying-latest-windows-7-image-from-wds You may ultimately have to reinstall the OS, but wait for some more info first.
