In Excel, click on Tools | AutoCorrect Options | AutoCorrect tab, and
delete the AutoCorrect entry for (r).

Yeller wrote:

edI recently upgraded from Office97 to Office 2003. In Excel 97 when I typed
(R) that's what I got. Now, in Excel 2003, when I type (R) it automatically
gets converted to the register symbol (the letter r in a cicrle). I have a
spreadsheet on movies I've taped and always list the film's rating, i.e.,
(G), (PG), (PG13), (R), etc.