Your colleague could have reset a toolbar or two.  But that's not under
Tools|Options.  It's under Tools|Customize.

Tools|Customize|toolbars tab
select each of the toolbars you want to reset and then click the reset button.

You can reset all the toolbars by doing this:
Close excel
windows start button|search
look for *.xlb
(Look in hidden folders for hidden files, too)

rename them all to *.xlbOLD

Restart excel to test it out.

If it worked, delete those *.xlbOLD files.

If not close excel and rename them back to *.xlb.

This will remove any customized changes from your toolbars.