Hi SuperJava,
Thank you for your post, I will do my best to help you resolve this issue.
I understand that your system does not boot into windows, but a blank or black screen. I see that you tried reseating the ram modules and switched positions, but there is no change.
Here is a link to a document on Start-up / Boot-up. There are some different links on it, that I think may help. A couple are testing the hard drive and troubleshooting no led lights, light or glow at startup. Please do not hesitate to reply, if you would like more help.