"my biggest question is if knoppix could have destroyed my hard disk? i have a vague presumption that if you mount a partion of a hard disk and you shutdown without unmounting it, you cause damage to that partition or even to the whole hard disk. is that correct?? or is every partition unmounted before shutting all processes down??"
There is a shutdown command. If you execute the shutdown command then shutdown writes all of the dirty buffers in the cache to the hard drive, umounts the file system, and then records the fact that the file system has been umounted in the file system superblock. If you come down hard without going through the shutdown command then you may have a corrupt file system and for sure you will not have the clean umount flag set.
When you boot after a hard shutdown then you will go through grub OK and load the kernel OK, unless the unwritten dirty buffers happened to be updates to grub or the kernel. When the system begins mounting all of the file systems in /etc/fstab you will get error messages saying that you need to run e2fsck against the file systems that were not dismounted cleanly. So the symptoms that you describe are not very likely to be caused by a hard shutdown in knoppix.
"the strange thing is that now the bios searches a SCSI device instead of an IDE device. i tried to let my bios auto-search my primary and secondary master and slave devices, but all it found was my CD-ROM drive as the secondary slave (or master, i forgot). so it didn't find any primary devices."
I do not think that your problem is software related. The BIOS is failing to find your hard drives and is not getting to the point of reading the MBR and starting grub. I do not know what triggered the problem. Did you have power fluctuations or the dog chewing on the power cord or something like that? In any case the solution is to get the BIOS to recognize the hard drives to where it goes back to the message, "searching fo boot record from ide-0 .. ". Play around with the BIOS hard drive configuration settings and see what you can do. If you have a corrupt BIOS you may have to flash your BIOS (reload the BIOS program) which somebody else will have to explain how to do since I have never done it.
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