Re-Installing Windows XP in "Repair" Mode... DVD Combo Drive Issue

My computer recently started locking up within a minute of booting up. I tried fixing the proglem by booting into "safe mode" and then choosing a Restore Point to a couple months in the past. This did not resolve the issue. In fact, it caused a new issue. After rebooting, a Nero Check box popped up and informed me of some DVD drive issue that it needs to fix, by rebooting. So I did, but it did not fix it. I noticed in Device Manager that my DVD drive was not working properly (the yellow question mark next to the drive). So I booted again into Safe Mode because that is the only way I could boot up without locking up. Then I uninstalled Nero. But the DVD drive still had the yellow question mark in Device Manager. At this point, I SHOULD HAVE tried to resolve that issue, but I decided to use my Windows XP SP2 disk to re-install windows and try the "Repair" mode to refresh my windows installation, hoping that would resolve the issue. It booted fine, from the windows cd and started the repair. About 20 minutes into the installation, it said that it needed to reboot in order to continue to the next step. Now this is where my situation got worse. It rebooted and asked me to insert my windows cd, but now it won't recognize the cd cause of the previous DVD device issue. So I am stuck. I can reboot my computer all day long and it will not get out of the Windows Setup. It is basically in the middle of a windows repair installation, with a dead dvd/cd drive and can't move on to the next step in the repair installation sequence. HELP.... I called microsoft, but they were of no help. They told me to call a hardware technician to fix the dvd/cd drive. Then they will help me after that. But I think there is a way that I can do this myself. --- When I am in the windows setup screen, which asks for me to insert the windows cd, I can press Shift-F10 and get to a command prompt. So I think I can work from there to resolve the dvd/cd drive issue. I just don't know how. I figure I can download a device driver from the dvd manufacturer's website and put that on my thumb drive then from there I can xcopy it to my c:drive and get my dvd/cd drive working. Is that possible? If so, where do I copy the file to? Or is there a way to access my windows registry and manually edit it to resolve the issue? I've heard about regedit.... can I use that? --- What should I do next?

Any help is appreciated... Thank you.