Unfortunately, when your credit history is less than fantastic - because of making payments after the due date, having too many credit inquiries, or even having mistaken information associated with your identity - you'll have fewer options when you need to make a major purchase. You may even have to pay higher than average rates on your car insurance or your mortgage.
If you find information that is incorrect, you can file a dispute. Remember too, that items on your credit report that you don't recognize could also be potential signs of fraudulent activity — someone working to secure credit in your name for their own use. Make sure you're clear on items that could potentially be fraudulent, versus those that may simply be inaccurate.