Most manufacturers no longer provide discs with new PC's, not sure if yours falls into this category but if you didn't get one and didn't create one when you received your PC you're in a bit of trouble.
I was in a similar situation with a stock computer and was able to retrieve important documents through a bootable Linux OS, but if you don't have any technical knowledge this might seem a bit difficult. As Route said, if you have any family/friends or colleagues that would be willing to help that's your best bet, because going with a professional will likely cost you.