Rename your file without bracket characters ([ or ]). See:

http://support.microsoft.com/kb/q215205/

In article ,
"InexperiencedExcelUser"
m wrote:

When I go to rename a worksheet it puts ".xls]' in fron to the name. When I
delete this it still comes up with an error and won't let me proceed.
Is this a bug? If so, does anyone know how to rectify?