Hi Diane,

   This isn't guaranteed to solve the problem, but it's worth a try. Use
Windows Explorer to search all of your hard disks for files with a .XLB
extension. Delete any that you find. Note that these may be a hidden files,
so you'll need to set Explorer to show hidden files before searching.

   Excel uses these files to store information about its toolbar
configuration, but they frequently become corrupt and cause strange errors
like this. Excel will create clean new default versions after you delete the
old corrupt ones, but you will lose any toolbar customizations you've made.