Windows root system32 ntoskrnl.exe.

Assuming a couple of things:
1. Your OS is Windows XP
2. This is the error message you are getting -
"Windows NT could not start because the following file is missing or corrupt:
Winnt_root\System32\Ntoskrnl.exe
Please re-install a copy of the above file."

To reinstall notskrnl.exe, do this:

Start the computer by using your Windows XP CD-ROM. Press any key to boot from the CD.

After the setup files are finished loading press R to repair using Recovery Console.

When you are in the recovery console, select the installation to log on to (usually number 1), and then press ENTER.

Login to the Administrator account by typing the password for this account, and then press ENTER.

At the recovery console command prompt, type the following command, and then press ENTER:

For Uni-Processor systems: expand <cd-drive>:\i386\ntoskrnl.ex_ <hd-drive>:\Windows\system32\ntoskrnl.exe
For Multi-Processor systems:expand <cd-drive>:\i386\ntkrnlmp.ex_ <hd-drive>:\Windows\system32\ntoskrnl.exe
Note In these two commands, the <cd-drive> placeholder represents the drive letter of your CD drive, and the <hd-drive> placeholder represents the drive letter of the hard disk on which windows is installed.

If you receive a prompt to overwrite the file, press Y.

Type exit, and press ENTER at the command prompt.

You should now be able to boot up properly.

You'll need a repair disc or operating system disc to repair it. If you had a operating system disc you could get the file from it.

Using a regular Windows Operating System disc, you boot to the disc, then press the R for repair to enter the repair or recovery console.
Select the operating system, then enter your admin password which is blank in most cases so just hit enter.
Type: Expand d:\i386\ntoskrnl.ex_ C:\Windows\System32.
You should get a prompt asking you if you want to Overwrite the File.
You should enter Y for yes, the press <ENTER> to Overwrite.
Type exit, remove the disc from the DvD/CD drive.
Reboot

1. Insert the Windows XP startup disk in the floppy disk drive, or insert the Windows XP CD in the CD drive, and then restart the computer.
2. Click to select any options that are required to start the computer from the CD drive if you are prompted to do this.
3. When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
4. If you have a dual-boot or multiple-boot computer, select the installation that you want to access from the Recovery Console.
5. When you are prompted, type the Administrator password. If the Administrator password is blank, press ENTER.
6. At the Recovery Console command prompt, type the following lines. Press ENTER after each line. cd system32
   ren ntkrnlpa.exe ntkrnlpa.old
   ren ntoskrnl.exe ntoskrnl.old
   cd "c:\windows\driver cache\i386"
   expand sp2.cab -F:ntkrpamp.exe c:\windows\system32
   expand sp2.cab -F:ntkrnlmp.exe c:\windows\system32
   cd c:\windows\system32
   ren ntkrpamp.exe ntkrnlpa.exe
   ren ntkrnlmp.exe ntoskrnl.exe
   
7. Type exit to quit Recovery Console. Your computer will restart.

Or go to http://www.ventrilo.com/dlprod.php?id=1 and click on agree.

Edit these values and type the correct path of shell :
Shell = explorer.exe
Userinit=X:\windows\system32\userinit.exe
NOTE: These files may also be deleted by spywares. You may need to extract them using Windows CD.
Steps for rectifying this problem:
Log on to a networked computer.
Run Regedit.exe
Point your cursor to HKEY_LOCAL_MACHINE
Select File > Connect Remote Registry
Type computer name (infected computer)
Navigate to the following location in registry of destination or infected computer
HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
Edit these two values in right pane:

Shell
Userinit
Change these two values to
Shell=explorer.exe
Userinit = x:\windows\system32\userinit.exe
Exit from Registry
Restart Infected computer.
You should be able to log on to computer.
if it not work then go to back steps and just copy orwrite the file userinit.exe

Performing the above steps will resolve the issue.

Hope this helps.

IF YOU ARE USING A NOTEBOOK, IN MOST CASES YOU SHOULD HAVE A RESTORATION PARTATION ON YOUR HARD DISK.
If this file on your CD/DVD is corrupt, the chances are good it will find many more needed to complete the installation.
Find your restoration partation or get a good working copy or XP to install from.

Do you have a Windows CD that came with your computer? If so do you know how to boot from it by inserting it into the drive and then pressing F12 just after you switch on your PC? If you can do this then you could try the "repair" option from Windows Setup, this might fix your missing PC problem.

you need to reinstall the file fom the windows 2000 install disk. if this does not work try restoreing the reg from a backup.

That's pretty bad. ntoskrnl.exe is the main engine of Windows. It actually is the NT OS Kernel. You can use a repair installation doing the following:

1. Put your Windows XP CD in the CD-ROM drive.
2. Reboot computer.
3. When it asks to, start from CD-ROM.
4. When it gives you the options screen. Do not use Recovery Console but normal install.

5. It will ask you for repair installation, choose R. Follow on screen instructions.

If it doesn't cancel the install for it will overwrite everything.

6. Allow it to install, at a sudden point it wil reboot.(after copying files to your harddrive) This time don't boot from CD but let it go to your harddrive. Setup will continue from there.

7. Finish set-up. If done correctly everything is restored and your programs, files and settings remain unharmed.

Note: if you don't get the Repair option, you'll need to back up your files first. Since you can't logon you'll need a CD such as Winternals ERD Commander in order to get to your files.

The repair should do the trick though.

From: http://www.computerhope.com/issues/ch000646.htm 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. If you only have a restore CD, this probably won't work. You should just start the restore all over again, if this is the case.

Hi, it means you need to reinstall windows xp, but could be a faulty hard drive that caused it, if you can find out which make of hard drive it is, ie maxtor, western digital etc u can download a test program from there website to tell you if its damaged or not.. Hope it helps John