If I am interpreting this correctly you have the worksheet or worksheets
within this workbook looking like they are in a different window (they have
been minimised). If this is the case then above the column headings (A B C D
etc...) on the right hand side and below the Menu items you will see the —▀X
buttons. (these buttons will also be missing on the Menu items line) Click
on the ▀ and the worksheet will now appear as normal. If you cant see the
—▀X then drag the worksheet to the left until they appear.
I hope this makes sense and helps