Richard mentioned helping you recover the data before restoring. Here are some things to consider.
I'm not sure if you need to restore with the DVD because they think it's a software problem or because they wiped the drive clean during what they did. Even if you once had a Recovery Partition (which i sincerely doubt), they may have wiped that as well. Whether or not and how we can help you recover any important data that was/is on the drive depends a great deal on what actually happened - it would help to know from the people who worked on it what exactly they did in terms of the hard drive (while you're on the phone with them anyway).
In one case, it may be as simple as booting to a special disk to get access to the drive (or slaving the drive to another computer) and then copying what you want to save to something (an external drive, another computer, a Flash Drive (if big enough), or a CD/DVD (unless using it with the special disk so you can't use it for copying). In another case, it may be very similar to that except we would only be able to use the slave process and recovery software which may or may not work and if it does work may recover very little, some, many or even most of the data - though my experience has been it recovers very little in such cases.
In either case, we'll help walk you through the process and provide links as needed (or advise you of your options if those aren't possible or don't work).
I hope this explanation helps you understand the alternatives a little better and what else to ask if you talk to the repair people again.
Good luck!