personal.xls is used by many to hold macros that users want available whenever
they open excel.
But most users have this workbook hidden.
If you want to hide the workbook, but keep it open...
Open excel (so only personal.xls is open and visible)
window|hide
Close excel--but answer the "do you want to save personal.xls" prompt with a
Yes.
The next time you open excel, personal.xls will be open, but hidden.
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If you really want to delete that personal.xls, close excel, use windows search
to find that file (look in hidden folders, too!) and move it or delete it.