Access Violation in Explorer when Viewing *.ht file Properties

• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server version 4.0

SYMPTOMS

If you have a debugger running and you open the property page for a hyperterminal session file (*.ht), and then close the property page, you will receive an access violation in Explorer.exe.

NOTE: *.ht files can be found in %winnt%\Profiles\<username>\Start Menu\Programs\Accessories\Hyperterminal.

CAUSE

HyperTerminal calls RegOpenKey to duplicate a handle to a registry item. But RegOpenKey does not duplicate the handle, it just returns the one you gave it (for example, the Shell's handle). Later, the HyperTerminal .dll closes this handle, and then the shell attempts to close the handle that was already closed by HyperTerminal.

RESOLUTION

HyperTerminal now uses RegOpenKeyEx, which does give back a new handle to the same item (in other words, duplicates it correctly), instead of RegOpenKey.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0. This problem was corrected in the latest Microsoft Windows NT 4.0 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K