Update: Very bad experience. I had access to the scanned images of the media today. I called up Microsoft Customer Support. Fed in all the inputs they needed (a lot!). In the end, I am stuck with this guy. I tried explaining him my situation that I do not have the disc with me. I got the scanned copies as the other guy had asked one day. I just mentioned to him that I installed my Windows 7 using another disc. He just went ballistic on this point. He pretty much claimed that I was breaking rules by using a third party image to install Windows 7. It was not allowed. The tone was pretty much like I was breaking some law and I should be punished for that. In the end, he refused to help me out. I felt like I was being treated like a thief and not a customer. I tried calling in again. The second time was a disappointment as well. I was told that the copy I supposedly own has been activated on four different machines so I was again committing some kind of a felony. I tried my best to clarify that it could not have been possible. They were not interested in helping me out. Asked me to provide them with more proof of purchase (scanned copy of bill, scanned copy of both sides of DVDs, my contact details etc etc.) In the end, I had to contact the Microsoft US Customer Care center (Brian helped me out with this one). It worked fine through a voice activated mechanism. No need to talk to any person. I am pretty sure that if I was at fault, their automated system would not processed the activation for me.
So, I changed by motherboard and processor that was powering the desktop running Windows 7.
I knew that the hardware change would trigger the Windows Activation mechanism.