I need help. I have tried everything on the Microsoft website concerning issues installing Microsoft Security Essentials. I have had MSE since it first came out. The other day I was using my laptop and all of the sudden I noticed the MSE protection icon beside my clock vanished. When I tried to restart MSE it stated that the exe file for mse could not be located. I located it myself and when I clicked on it I got the same message. I then uninstalled MSE and downloaded and attempted to install a fresh copy of MSE. Now all I get is the "Cannot complete the Security Essentials Installation. It also lists error code : 0x80070780. Again I have tried all of the suggestion on Microsoft websites and NOTHING has worked. Does aannyone have any clue what is causing this problem? Can anyone help?