1)Open the HTML Help project.
2)Select Project > Open > Pods > Output Setup. The Output Setup pod appears.
3)Open the Context-Sensitive Help folder.
4)Open the Text-Only Topics folder.
5)Select Context.Txt (the What's This? Help file).
6)Click Delete .
Version-control projects may have more options.
note: You can restore a What's This? Help file. The What's This? Help project file (.CHJ) remains in your project folder, and you can import it into your project to create a CONTEXT.TXT file. See Importing What's This? Help projects into HTML Help projects.