I, trying to manually modify my boot screen in windows, replaced ntoskrnl with a corrupt file (don't worry I saved the original and it's under the name ntoskrnl.bak). But now windows won't boot. What we've been trying is using a bootable version of knoppix to modify the files and get them back to normal, but I've never used linux before and for some reason it won't let me change, delete, or rename and of the files in my hard drive. If you can think of any other way to fix this problem, or detail to me very simply (first time using knoppix) the process to delete one file and rename another in my C drive I would be eternally grateful, thanks.

you could try to boot from a win 98 or me boot disc but if it is an ntfs file sys i think it may be toast.

boot from Win XP CD (I am assuming XP) and run Reovery Console and copy over ntoskrl from the cd using cmd line commmands. That should work.

Give that a try.

Also, make a fully contained XP CD. http://www.nu2.nu/pebuilder/