Oh, even easier then!
You don't give your other fields in the table, but I'll assume that you have employeeID and employeeName in there, too. Since you presumably want the payout for each employee.
SELECT employeeID, employeeName,
IIF( [Transaction Errors] > 6, 0.0, [Potential Payout] ) As ActualPayout
ORDER BY employeeName
If you mean that you want to UPDATE the table to change the value of the [Potential Payout] field to match, then that's just as easy:
SET [Actual Incentive Calculation] = IIF( [Transaction Errors] > 6, 0.0, [Potential Payout] )
This all *assumes* that you have ONE RECORD in this table per employee. If that's not true, then you need to give many more details, possibly including some sample data (okay if it's dummy).