ntoskrnl.exe HELP

I believe that i have a virus that currupts the ntoskrnl.exe file in system32 folder of an CP computer. My computer crashed over the weekend giving this error every time it boots

"Windows could not start because the following file is missing or corrupt:

\system32\ntoskrnl.exe.

Please re-install a copy of the above file.


Two days later my stepmothers computer went down in the same mannor. Basically i am looking for a virus that would do this, and i need to know how it saves itself on the computer because i can access my hardrive through an ntfs reader and see if a file is there, if i know what i am looking for and where it would be saved. for example the Fun Love virus saves it self as FLCSS.EXE in the windows system folder. I can check to see if the FLCSS.EXE is there, and if it isnt move on to the next virus on my list. I need to know what this virus is, because i personally own 5 other computers that are at risk to get it.

 

Yup i have already checked out both of those sites, because of the way my computer crashed, and becuase a commputer that mine has shared files with in the pase went down in exactly the same mannor two days later, i really suspect virus, and that is pretty much the only thing i am currently concerened with. I can fix my broken computer later, but i need to protect my working ones first