A similar problem, when using an Internet cafe or indeed,
anybody else's computer.
If you use, say WORD, to write a letter and then print it and copy the file off to diskette, you will leave a partial copy of the file on the machine.
This is because WORD opens temporaty files during the editing process and these are not always deleted automatically. Also, some folks do not check to see if the Auto-Save function is on, this can also leave part files behind. Mind that I say
may as different versions do different things and the set up of the machine may also affect it.
A couple of years ago I was staying in the Hyatt in Jo'burg and used their biz facility to do e-mail and write some items. After I had deleted the Internet Cache and checked for stray copies of my documents (Simply using Windows Explorer) I found in the 'My Documents' a whole series of letters that had been written on that PC by a number of different people. One of them was by a company seeking govertment contracts and was addressed to the president of the country!!
Not for a moment do I say that the Hyatt were keeping copies of guest correspondence - Microsoft WORD was doing that automatically
So, please check that you delete and files for WORD or EXCEL etc. One of the best ways is to ONLY use your own floppy disk. When you create the document, start the very first save on the floppy. Although temp files will still be created, WORD responds differently in my experience to documents on floppy disks.