Ntoskrnl.ex_ problem

I have installed TUNE UP 2008 from ACE utilities. When I restart my PC, it tells me that the file NTOSKRNL.EXE is corrupt or missing. I must admit that I have used the WIPE DISK option on TUNE UP 2008 to wipe my harddrive and clean it from old files and malware etc.
Must I re-install XP or can I expand NTOSKRNL.EXE from the SETUP CD of XP?
If I can expand it, how do you do it?
Please help, I don't want to lose important data.

 

Here are a few thing to try. In the following commands, C: represents the hard disk and D: the CD/DVD drive, change them as necessary to suit your configuration.

1. Boot the XP CD and select the first repair option (R) which will take you to the Recovery Console. Now copy the missing/corrupt file from the CD to your hard disk by typing "˜copy D:\i386\ntoskrnl.exe C:\Windows\system32\ntoskrnl.exe’ (not the quotes but the two spaces) and press Enter.

2. If you can only find ntoskrnl.ex_ on the CD then the file needs to be expanded by typing "˜expand D:\i386\ntoskrnl.ex_ C:\Windows\system32\ntoskrnl.exe’ (not the quotes but the two spaces) and press Enter.

If 1 and 2 above do not work, rename the file by typing "˜ren C:\Windows\system32\ntoskrnl.exe C:\Windows\system32\ntoskrnl.old’ (not the quotes but the two spaces) and press Enter. Then try again.

3. If it’s still not working, in the Recovery Console type "˜chkdsk /r’ (note the space) and press Enter.

4. Try method 2 as outlined here http://support.microsoft.com/kb/314477