Anytime I tell the comp to shut down instead of the option to shut down comes..instead I get a box saying Microsof Windows Explorer encountered a problem and hence needs to close. I have run Antivir Virus, Hijack This but yet it has detected nothing. First it used to happen when I run my Total Video Converter or Realplayer but a couple days now I have seen it doing it almost everyday. This problem has been happening for 2 months now