not access to window or MS DOS

Hello!
After apply some changes with magic partition software and restart. My laptop has a black screen with a flashing cursor at the left hand side of the screen.
You can acces BIOS but nothing else, not windows not MS DOS.
I try to reboot the system with a flooppy disk and a CD but it?s not luck.
I also try to updated BIOS but nothing happend.
When this happend the computer was working with the battery.
My laptop was working fine before use this software…
Any ideas?
Please help