Is my computer dead?

I put my 2008 MacBook up for sale a week ago, somebody bought it. I inserted the install disk in and started to re-install the operating system. As it was booting up from the disk, I went downstairs, when I came back up and it had stopped, I tried turning it on again and I get no response. I have recently brought a new battery and charger and it does not seem to work. It has got my disk trapped inside and I really need it fixed urgently.

Thanks in Advance