If a bank catches up with u after 9 yrs of owing them money r u better to pay it off or bits for cr rating?

My fiend owed a bank money ages ago and done a runner in fright. he has since had loans mortgages etc and paid them all ok. is it best for him to pay off outstanding all at once or just small installments, is his credit rating buggered for good anyway?
Answer
My comprehend ing is that after 7 years they cant touch you for a penny anyway