According to law each and every citizen must have free access to their own credit report and it is recommended that you check it once a year in order to be sure that the information is correct. As all the information is entered by data entry personnel it is entirely plausible for mistakes to me made and if left uncorrected then they will continue to show up in future credit reports.
In case that you notice any false information listed about your financial history, you can then file a credit report dispute. When you do this make sure that the credit reporting agency will correct the mistakes as obliged by the Fair Credit Reporting Act.
When submitting a dispute letter you need to include all of your claims in writing and to describe them with as much detail as possible in order for the errors to be located and fixed as quick as possible. If you can it is also a great help to include any supporting documents you might have such as receipts, tickets, notes, invoices etc. Dont forget to make a copy of everything you have stated as well as all the documents you attached to your dispute letter.
When you file your dispute an investigation will start and your claim or claims will be assessed for their validity to be proved. After the investigation has finished, and your claims have been proven true, then any errors in your credit report will be corrected.
For more information, here's a good read on how to dispute your credit report with a sample of dispute letter for your perusal.