MacBook freezes once it starts up.

I had been working on reinstalling snow leopard back onto my computer because it had been acting up lately and running slow, therefor I reinstalled original software with the discs it came with. I was messing around with disc utility and restarted my computer. When it rebooted the screen was exactly the same with the same windows open as before the restart, but the mouse was stuck in the upper left corner and it remains there still. I have tried to take the battery out, I've tried putting in both install discs again and it will read the disc, but I cant utilize them without any control of the mouse.

Im able to get it to start in safe mode, but again it brings me to the "safe boot" window asking for my password, but I can't use the keyboard or mouse.

Please help!