Each time it restores autoexec.nt

Error pops up “windows file protection” Stating thet”File that are required
for windows to run properly have been replaced by unrecognized versions.To
mainain system stability windows must restore original vertions of therse
files.” and it ask for cd.Each time it restores autoexec.nt on each restart.

Recovering the same file has no effect.Kindly suggest the beeter one.