Accurate derogatory information remains on your credit report for 7 years and there is no legitimate way to remove it, no matter what a "credit repair" company might advertise.
You can correct inaccurate information by contacting the lender(s) and the 3 credit bureaus and filing appeals.
If you get all 3 full credit reports from www.annualcreditreport.com, they will include contact information and other details about how to dispute or appeal a negative item.
