How to deny delete/modify permission to a file?

I want to deny myself the ability to modify or delete an executable.

When .NET Reflector asks you if you want to update:

and you choose No it spontaneously deletes itself as retribution:

So I want to prevent myself from being able to Delete the executable; as punishment for their punishment.

I tried to Deny me Write permission (and deny it to Everyone, and Administrators):

Except, I can still Right-Click -> Delete the file...

How do I deny the delete/modify permission to a file?

On Windows, it is enough to have one of:

• "Delete" on the object, or
• "Delete child" on its parent

Therefore a file will only become undeletable if you deny both.

Use icacls to edit the permissions:

• Deny "Delete" to the file:

  icacls Reflector.exe /deny Everyone:(D)
  

• Deny "Delete child" to the folder:

  icacls . /deny Everyone:(DC)
  

_{(Tested on Windows XP.)}