Windows XP won’t boot; Black Screen

My colleague tried installing windows 7 on a computer pre-installed with Windows XP and in this process the computer lays lifeless, shows black screen and won’t boot up.
I tried everything from restarting… All connections intact… pressed F8… but to no avail.
Is this a hardware issue? I believe that the configuration won’t support Win 7.
Will reinstalling Windows XP solve this issue.

Please assist. Thanks in advance.