I have an old Toshiba Satellite Pro 430CDT labtop that i crashed by deleting system files (i think). When I reboot the computer all it says is "INVALID SYSTEM DISK Replace the disk, and then press any key", press all the keys you want it keeps saying the same thing. I would like to give it to my friends little son to play/learn with. How do i reboot the computer or reinstall the entire system or are there any sites i can go to in order to get the proper software to download that will fix this problem?