eh...
how is it possible that you have a primary key containing duplicates?
in the table, set the field index to not include duplicates...
anyway, back to your problem...
You need something like:
SELECT DISTINCT pKey, count(pKey) FROM tblName WHERE count(pKey) > 1;
this would give you all the pKeys that occur more than once in the table...
if you'd like to delete those records, then put a delete in front of it...
DELETE FROM tblName WHERE pKey = (
SELECT DISTINCT pKey, count(pKey) FROM tblName WHERE count(pKey) > 1
);
fiddling might be required...