Vista can't find setup file

Hi, when I start computer, it seems ok until suddently a black screen showed up, a message says 'can't find setup file".

I can still use Ctrl-Alt + Delete function, but the pc just can't finish the final boot step.

Does anybody know the solution? Does it mean the pc has been affected from virus?

Thank you.

I suspect, I am not sure, that your setup file failed its installation of something. Read this to try to fix that, run the windows installer cleanup utility.

http://support.microsoft.com/kb/290301