What is the name of the program that your using to modify the context menu?
What I'm saying is to locate the program that placed open with text Editor'
open with Hex editor
Open with Generic Editor
calculate Hash values
I'm assuming this is some type of hex editing program like Winhex, correct?
If Windows Picture Viewer is you default graphic viewer you cannot remove Preview, set as background, rotate, etc
If this just occurred, can you go back and do a restore to an earlier time to bring back the default menu?