Just some more questions...
If you rename a sheet in a brand new test workbook, does excel crash?
Is the crashing limited to a single worksheet in a single workbook?
If it's just a single worksheet or just a single workbook, maybe it's not
excel--maybe the workbook/worksheet is corrupted.
You may want to start rebuilding that worksheet and replace it with a new copy.
(Or rebuild the whole workbook if it's all the worksheets in that workbook.)