The .exe keeps deleting itself

I have been using the emulator just fine for about a week now, but today when I went to load it up (after having played last night) the .exe was just gone.  So I grab another one, try to toss it in the folder, it wont let me due to folder permissions (I checked, full permissions, no restrictions).  So I download a new copy of the emulator, boot it up.  Within one second it crashes and deletes the .exe.  I have gone through this process about 5 times and every time the same result, it deletes the .exe.  Any solutions?  It is driving me insane because it has been working flawlessly all this time.