Try right clicking on the original sheet and selecting 'move or copy'. At the top of the small window that opens click on move to and 'new book' or any other workbook that is open including the original. Be sure to select the 'create copy' box at the bottom unles you want to move the sheet and not leave a copy behind. You can also use this to move/copy sheets between a workbook which is useful if you have hundreds of sheets in one book (like I often have!) and want a sheet moved/copied next to another one far away.