NTOSKRNL.EXE is missing or corrupt.

startup environment.

Missing or corrupt ntoskrnl.exe file

If the ntoskrnl.exe file is corrupt or missing this can also generate the error. To restore this file follow the below steps.

1. Insert the Microsoft Windows XP CD. Note: If you have a recovery CD or a restore CD and not a Microsoft Windows XP CD it is likely the below steps will not resolve your issue.
2. Reboot the computer, as the computer is starting you should see a message to press any key to boot from the CD. When you see this message press any key.
3. In the Microsoft Windows XP setup menu press the R key to enter the recovery console.
4. Select the operating system you wish to fix, and then enter the administrator password.
5. Type expand d:\i386\ntoskrnl.ex_ c:\windows\system32
6. You will then be prompted if you wish to overwrite the file type Y and press enter to overwrite the file.
7. Type exit to reboot the computer.

Windows NT installed on a partition bigger then 7.8GB

If you are running Microsoft windows NT 4.0 on a partition larger than 7.8GB this issue can occur if the boot files are located outside this limitation. When this error occurs your computer will have the error message as shown below.

OS Loader v4.01
Disk I/O error status=00000001
Windows NT could not start because the below file is missing or corrupt: winnt\system32\Ntoskrnl.exe
Please reinstall a copy of the above file.

If your system partition is larger than 7.8GB you will need to delete the partition and recreate the partition to 7.8GB or less. Additional information about this issue can be found on Microsoft KB Q224526.

Corrupted hard disk drive or severely corrupted Windows

Attempt to check the hard disk drive for any errors by running the chkdsk error. To do this follow the below steps.

1. Insert the Microsoft Windows XP CD. Note: If you have a recovery CD or a restore CD and not a Microsoft Windows XP CD it is likely the below steps will not resolve your issue.
2. Reboot the computer, as the computer is starting you should see a message to press any key to boot from the CD. When you see this message press any key.
3. In the Microsoft Windows XP setup menu press the R key to enter the recovery console.
4. Select the operating system you wish to fix, and then enter the administrator password.
5. Once at the recovery console type chkdsk /r
6. Once completed type exit and see if issue is resolved.

If after trying all of the above steps you are still encountering the same issue it's likely that Windows is severely corrupted and it is recommended you attempt to reinstall Windows. Additional information about erasing the computer and starting over can be found on document CH000186.

Finally, if during the Windows installation you encounter errors it's likely that your hard disk drive is bad.