Help becomes disabled
 

I have noticed that on some machines the Help feature
is "disabled". The Help screen appears but the mouse
pointer turns to a double-arror and key strokes and mouse
clicks are ignored. We are in a classroom on a mirrored
installation. Help works for some but not for others. It
doesn't seem to be an error-while-using issue because for
those for which it works it always works and for those for
which it doesn't it always doesn't. Any ideas?