Reinstall ntoskrnl.exe

I just did a Windows update and downloaded KB831240, KB822603 and Windows Error Reporting. Upon trying to restart my computer, I found that this drive would no longer boot up. The message given was:
Windows could not start because the following file is missing or corrupt
<Windowsroot>\system32\ntroskrnl.exe
Please reinstall a copy of the above file.

I went into my other HD and copied the ntosjkrnl.exe file. When I attempted to paste it into where the file was in my not working HD, I got the message:
The C:\WINDOWS\System32\ntoskernl.exe application cannot be run in Win32 mode.

How do I fix this problem without having to reinstall WINXP all over again?

 

Note your Windows directory is windows not winnt

Well maybe. If the system was a fresh load with XP, then the default %systemroot% is Windows. But if you upgrade from 2K, it remains as WINNT.

 

I'm sorry. I couldn't seem to follow it. I pressed F8 to try last known good configuration, but nothing happened. I tried safe mode, but it told me I needed to reinstall ntoskrnl.exe. I deleted it in c:\WINDOWS\System32, then copied it from my good D drive and pasted it into where I had deleted it in C. It still has the same problem. When I put in my XP CD, I am given the option to repair, but it asks for my administrator password, and I never installed one. Anyone willing to walk me through the process?

 

Pete,
Thanks for the help. I did hit enter for the blank password, but it just gave me the continued c prompt, unless I was supposed to do something there. Also, I do have XP on both drives, for specifically this purpose. It gives me a backup computer when one drive is having problems. I just keep my son's games on the larger drive.
Anyway, I think I resolved it on my own. Apparently, when I deleted the exe then copied and pasted it, I wasn't supposed to hit restart, but shutdown, as when I started my computer this morning, it works fine. If you can explain what I did, I may understand it better for future reference.
Barry

 

This is the 2nd time the ntoskrnl.exe got corrupted in one week. Now that I know how to fix it, I have that HD up and running again, but is there anything I should be checking to determine what might be causing the problem?

 

Pete,
Thanks for the suggestion, but it didn't find any bad areas. Anything else I should check?
Barry

 

It's time for a System File Check
Start > Run > cmd
sfc /scannow
XP install cd needed

sfc - system file checker, retrieves the correct version of the file from %Systemroot%\System32\Dllcache or the Windows installation source files, and then replaces the incorrect file.

If you want to see what was replaced, right click My Computer > manage, expand event viewer > system.

HTH
Johanna

 

Johanna,
It just did 28 different information types. I'm not sure exactly what it did, but I guess it fixed whatever needed to be fixed. Did it undo any Microsoft security fixes? Thanks for the help.
Barry

 

Most of the time, MS Updates are safe from SFC, but to be sure, go to the site and let MS scan your comp to see if anything needs replaced or added. Post back if it gives you any more problems.

Johanna

 

Thank you Johanna. I will. I'm not sure that going to Microsoft will work, as I've had experience with XP security updates where I had to delete the update, but MS still had me on record as downloading it, so didn't say I needed it. I had to redownload it on another site.
Barry

 

Johanna,
I was hoping for the best, but I just had to reinstall ntoskrnl.exe again. Any other suggestions?
Barry

 

Barry - this file is a protected system file so if you delete it a replacement is immediately put in from your cached files.

If you happen to have a bad copy there, then when you run sfc and it sees a bad file, it will probably pull the replacement from the same source.

My guess is the file you have on your install CD is a good one so I think the trick here will be to force your system to pull a copy from the CD.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup\SourcePath

Put in the full path to the I386 folder on your CD or else copy the I386 folder to some new location on the PC and use that location.

As an additional precaution and before you run sfc, go to windows\system32\dllcache (probably hidden so unhide) and remove the read-only feature then delete the ntoskrnl.exe file that is there.

 

Newt,
I'm not sure exactly how to do what you are asking. I copied and pasted this file to my desktop, then removed the read-only feature from the system 32 drivers, but couldn't find source path, nor do I know what to do with it once I find it. Please give me more specifics.
Thanks,
Barry

 

SourcePath is a registry entry.

start~run~regedit and when it starts, you should find a section named HKEY_LOCAL_MACHINE - Once there just keep clicking on the plus signs to expand the sections until you find
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Setup\SourcePath and when you find it, click on Edit then on Modify and change the path to point to the I386 folder on your CD or if you copied the I386 folder from the CD to your hard drive, point the path to that.

Delete the copy of ntoskrnl.exe from windows\system32\dllcache.

When you run SFC /scannow it will pull a copy of the file from the I386 folder rather than using any (possibly damaged copies) that were on your PC before.

As a safety precaution since registry damage can cause major problems, I'd suggest backing up the part you will be changing before you actually make the change.

In this case when you have gotten down as far as \CurrentVersion\Setup in the left-hand pane, right-click Setup and choose Export. Enter a name and location that you will remember, and then click Save.

If you need to restore that branch of the Registry, all you need to do is double-click on the file that you just saved, and the information will automatically be put back in the original location.

 

Newt,
I found this before, but I still don't have source path. All that is listed after setup is:
BaseWinOptions
+ExceptionComponents
Migration DllS
+OC Manager
OOBE
+OptionalComponents
What do I do now?
Barry