Inquiries into a fair to bad credit file affect your credit score, and are not easily removed. In this case, it's better to be safe than sorry. Once you get your credit reports, check for ANY errors on it, including beginning dates of delinquency, dollar amounts of debt, or accounts that you don't remember having. You can write a letter disputing any items that are inaccurate. When you decide to dispute an item, make sure to keep a copy of the letter you send them as well as send it certified, return-receipt.
Some people also find it helpful to use a lawyer to write the letters.
If you can't afford to do this, you should also check our Pre Paid Legal plans in your area. Look in your yellow pages for your closest distributor of these plans. Once you have some information removed from your report, you'll be on the tight track. There will be some negative information you simply can't get removed or changed. There are plenty of consumer-oriented lawyers who can help you make your case.