I don't know how successful the following technique will be but it might work in some cases:
Based on a tip I posted in another thread,
OS choices menu, I wanted to see If I could make a floppy that would boot the system into safe mode. I did have success. In fact, putting my money where my mouth is, I deleted my boot.ini and ntoskrnl.exe from my system partition and successfully booted my system from the floppy. Placing the necessary files plus a modified boot.ini, the system was able to use the ntkrnlpa.exe to boot into safe mode instead of a missing/corrupt ntoskrnl file.
1) From a working 2k/XP system, format a floppy disk. It needs to be formatted from within windows. Insert disk into drive, right-click on the floppy drive, select format. Leave "create a msdos startup disk" unchecked.
2) From the root of the system partition, copy these files to the floppy disk: ntdetect.com, ntldr. These files are hidden so you will need to disable 'Hide protected operating system files': Go to Folder Options > View and uncheck the appropriate option.
You can also copy them via the command prompt:
xcopy /H c:\ntdetect.com a:\
3) Create an new text file on the floppy which will be saved as boot.ini. Place the following code in the file:
[boot loader]
timeout=5
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /safeboot:minimal(alternateshell) /bootlog /kernel=ntkrnlpa.exe /noguiboot
- [boot loader]
- timeout=5
- default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
- [operating systems]
- multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /safeboot:minimal(alternateshell) /bootlog /kernel=ntkrnlpa.exe /noguiboot
Usually the system partition is the first partition. If not, then you will need to modify both instances of partition(1) to correspond to your particular needs. If you don't know which partition is the correct one, just try 1, then 2, etc until you are able to boot.
Here's a link that explains the boot.ini in some detail:
http://is-it-true.org/nt/atips/atips136.shtml Thank you ATNO.
You may need to modify other aspects if you have a SCSI drive or are using another IDE chain.
When saving from notepad, wrap the filename in quotes to ensure that it doesn't get saved as boot.ini.txt.
Hopefully you will find yourself in safe mode with a command prompt. From there you can try to fix the problem; correcting boot.ini errors, replacing the ntoskrnl file, running chkdsk, etc.
It might be a good idea to make this disk now in case of future problems.
As I said before, I don't know how successful this will be. It certainly won't work for every case: Hardware failure or other causes where the ntoskrnl error is just a symptom. I plan to do more testing and compile a help text containing the different methods of recovery.
For the floppy to work, you need to set the floppy drive as the first boot device in the bios. This varies from system to system so I can't give specific instructions on how to do this. A simple web search will most likely yield useful instructions.
I would also appreciate others who want to test this on various Operating Systems: 2000, XP, 2003. No need to delete any of the above mentioned files.

. I'm just crazy. All that would need to be done is the creation of the floppy disk and a reboot of the system with the floppy.