Your question is (/was) very unclear.
Add more details:
- The schema (partial if necessary) of your table
- Exactly what columns have unique indexes
- The exact query that is failing, and why it is failing.
You're creating duplicates in your table - that's not allowed. But no-one can help you if we don't know exactly how you're creating those duplicates, except with wild guesses or potentially dangerous/drastic suggestions (like dropping the constraints temporarily).
Explaining what you're trying to do could also help giving you a good answer. Is this a one-shot data fixup that you're doing while the application is offline (i.e. no concurrent users), normal (periodic) maintenance, normal application code? etc.
Be careful with vocabulary too:
"I'm trying to update a table, but I am getting an insert error"
Update and insert are distinct things in SQL. Just that first sentence will confuse people about what you're trying to do. Be precise. Perfect grammar/English is not expected, but do try to use the right technical terms.
If you're not comfortable with english, add more "pictures", code, diagrams, whatever it takes to be sure people can understand exactly what you're talking about.
In short, people need to know what you're doing, and what you're doing it on, if you want relevant answers. Your question was not precise enough in its description of the situation and the problem.