I made a bone-headed mistake in one of my init.d scripts which gets stuck in an infinite loop during the boot process and blocks the completion. I therefore can not get to a shell and fix it. How can I boot and not perform all the boot scripts? I have root if necessary.
As Ignacio suggested, the simplest solution is to boot into single user mode. To do this press any key on the countdown splash screen before it boots into the kernel. From here highlight the proper kernel and press e. Press e again to edit the cmdline and at the end at either S, s, single, or 1. Press return and then b to boot. This won't run your init script unless you've explicitly configured it to be part of single user mode, which is unlikely.
However, if you still have problems at this point, you don't need the install disk. You can add the following to your kernel command line:
This will cause the kernel to start
...or you can remove the