Foreclosures are types of "charge off" listings that are devastating to the credit score, especially when applying for a mortgage. Much like a charge off or collection account, a foreclosure or repossession not only damages the score, but it's very difficult to remove by contacting the creditor.
One way to remove a foreclosure from your report is to wait out the 7-10 years for the foreclosure to drop off the report. For those who do wish to have access to credit need to start building new and better credit records. Some lenders will give less weight to a foreclosure if they see a few years of good, on time payments.
You may also want to contact a credit expert as they will know the ins and outs of the credit system.