LAST EDITED ON Apr-26-02 AT 11:49 AM (EST)
I have a Toshiba laptop. Windows NT 4.0 is installed on it. The hard
drive is configured as NTFS partition(s).
The laptop will not boot from the hard drive anymore. I get:
"non-system disk error -- ... "
Events that led to the problem:
(1) I was running service pack 3.
(2) I attempted to install service pack 6a.
(a) SP6a *seemed* to install correctly, and I re-booted the
(b) Upon (successful) reboot to the NT login screen, I logged
(c) During log-in ( start-up of desktop, etc., etc. ), the
log-in "hanged" during start-up of McAfee Virus Scan.
(d) I waited and waited and waited for McAfee Virus Scan to
finish it start-up ( i.e., for the logo to disappear from the center of
the screen display and to end up minimized in the lower right hand
corner of the screen -- the "tray" ).
(e) I gave up, and hard-reset the laptop.
(3) Upon re-start after the hard-reset, I got the proverbial:
NTOSKRNL is missing or corrupt
(4) I purchased and started messing with winternals software
( NTFSDOS, DISK COMMANDER, REMOTE COMMANDER )
(5) I successfully booted the laptop with Disk Commander on a floppy
(a) it scanned the hard-drive and identified "possible NTFS
(b) it successfully "searched to salvage" data files on the
"potential" NTFS partitions
(c) this reassured me that the data is salvageable.
(6) I then used Disk Commander to do some "writing" to the physical
(a) I "identified" one of the potential NTFS partitions as
a "real" one
( this represented a write / change to the partition table ).
(7) I shut down the laptop, and tried to re-boot.
(a) This time, INSTEAD of "NTOSKRNL" error, I got:
"non-system disk error ... please insert ..."
( of course, there was no floppy disk in the floppy
(8) I booted again from the Disk Commander floppy
(a) Again, successfully scanned the physical disk,
identifying current and potential NTFS partitions
(b) Did a "scan to salvage" on the partitions, and saw that
the data files were still visible / salvageable
(c) Did a " re-write the MBR"
( just shooting in the dark now )
(9) Tried re-booting from hard drive again
(a) Still got the " non-system disk error " error.
(a) Crashed my laptop while McAfee virus seemed to be hanging
during the very first log-in after updating from NT 40 sp3 to sp6a
(b) Attempted to reboot, got "NTOSKRNL corrupt / missing"
(c) Used an (excellent) third-party tool to boot and scan the hard
drive to identify NTFS partitions and salvage files
(d) Used the tool to make a change to the partition table
(e) Attempted to reboot, got "non-system disk error"
(f) Booted with the third-party tool again, this time using the tool to "re-write MBR" ( shooting in dark, not really knowing what i am doing )
(g) Attempted to reboot, still got "non-system disk error"
I seem to have corrupted the MBR and/or the master partition table of an NTFS-formatted hard drive.
And, at any rate, at root, it seems that the BIOS cannot find the (a)
location in the (NTFS-formatted) hard drive that tells it where to look for the (an) operating system.
*** ADDITIONAL NOTE -- Probably the root, root cause of the problem ( why VirusScan hanged when I rebooted after a clean install of sp6a is that the hard drive was infected by a virus.
So, once the MBR has been repaired, and the NTOSKRNL has been repaired, from the volumes of stuff I have read so far, it seems that actually re-booting might trigger the virus to start causing problems again.
If I get an answer to how to repair the MBR, I have Microsoft Tech Notes that explain how to repair the NTOSKRNL problem ( I hope they are right! ).
If that all succeeds, then dis-infecting the hard drive would be the next advisable thing, before re-booting for real. )
I have the latest version of Norton System Works ( I purchased it hoping to fix this problem, but it is not designed to do that, it would appear ).
Can I use System Works ( AntiVirus component ) or anything else to cleanly disinfect the hard drive ( remember, NTFS-formatted. )
Finally, I see a lot of suggestions re: using fdisk/mbr
But I believe that that is not use-able for NTFS drives.
WHERE WOULD YOU GO FROM HERE ??? !!!
I have a feeling this is not so hard to fix. Either the BIOS does not know where to go to find the MBR, or it is told to go to the wrong place, or it is told to go to the right place, but the contents ( of the MBR ) is bad corrupt.
( I am partly using this as a learning excercise, because at this
point I am fairly confident I can recover at least my data files using
the winternals tool set ( although I will post a separate question about that ) , but I DO want to fix my hard drive to be able
to boot again, both to learn but also to use it! ).
Any help would be very appreciated.