format/reinstall debian from CD after wrong installation

Hi all,

I installed the newest debian stable wrong. I entered the wrong gateway IP. So the installation prozess couldn't load a mirror image. Now i would like to reinstall Debian with the right gateway IP and a mirrord image...

It wan't boot from the installation CD Can I enforce that?

I can't format the hole disk
The commands fdisk and mkfs aren't installed
Is there an other easy way?

I'm also quite new in Linux, so it's maybe a stupid question sorry bud i couldn't find a satisfying answer on the web!

Thanks!

Try changing the gateway first. Boot the system, log in as root, open /etc/network/interfaces in your preferred editor, and change the "gateway" line to the correct value. After that run

/etc/init.d/networking restart

and you should be done.