Ok my hard drive is failing so I'm going to replace it. I can't find my boot disk from the computer when I bought it. It's a dell xps 410 from about 7 years ago. It came with vista and I bought the win 7 upgrade. So my question is what can I do so when I put the new hard drive in I don't have to go buy a new copy of windows and what ever else I would need to get it working.