You will need to post to a more appropriate newsgroup.... this group if for a
scheduling application -- Microsoft Project.
That said, this may get you going in the correct direction. If you are
using a Windows Operating System such as XP, one of two things has
happened... either you have switched users and did not know it, or, you may
have a shared drive (folder) to another computer. In the worst case, if you
shut the computer down, the other user that is connected will be
disconnected. If the problem persists you probably have a mapped drive.