PRODUCT  :  Turbo Debugger                         NUMBER  :  648
  VERSION  :  2.0
       OS  :  WIN
     DATE  :  October 22, 1993                         PAGE  :  1/1

    TITLE  :  Common Causes of General Protection Faults in TDW




  The following are common  causes  for  General  Protection faults
  while debugging a Windows application  under  Turbo  Debugger for
  Windows (TDW.EXE):

    a) ram has called a Windows API function with incorrect arguments.
       For example, passing WndProc a handle which is invalid.

    b) The segment part of a pointer the program is using is invalid.
       In protected mode it is an index into the selector table which
       has the actual segment address.  If that index references a spot
       in the table which it shouldn't, or goes outside the bounds of
       the table, it can cause a GP.

    c) The user's WndProc function uses a handle between function calls
       which has not been declared static, so the value has changed.

    d) The CreateWindow API function calls your WndProc function with 3
       messages.  If WndProc is not debugged, it can cause problems
       (like a GP).

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