Norton CrashGuard 1.1 (Freeware Edition) Release Notes Copyright 1996 Symantec Corporation All rights reserved Please read this document carefully; it contains important information about Norton CrashGuard. What's New in CrashGuard 1.1? ============================= Activating Anti-Freeze with CTRL+ALT+DEL ---------------------------------------- CrashGuard can add an "Anti-Freeze" button to the Close Program dialog box which appears when you press CTRL+ALT+DEL. You can turn this feature on or off by right-clicking the CrashGuard icon which appears beside the clock in the Windows task bar and selecting "Add Anti-Freeze to Ctrl+Alt+Del" from the menu. Enhanced fixing of Multi-Threaded programs ------------------------------------------ CrashGuard now provides better repair for multi-threaded software (such as Microsoft Internet Explorer) by protecting the critical threads from crashes caused by an auxiliary thread in the same program. New crash context/risk analysis ------------------------------- Because a program may be about to perform a critical operation, CrashGuard now determines the potential risk of letting the program continue what it was doing when you select Fix. This helps prevent a malfunctioning program from causing any harm after a fix. Deleting CrashGuard ------------------- Please use the Add/Remove programs feature in the Windows Control Panel to remove CrashGuard from your system. If CrashGuard is unexpectedly deleted from your system, the system may not report program errors because expects CrashGuard to handle them. The system may suspend the program and leave it that way until you use CTRL+ALT+DEL to close it. You can correct this problem by deleting the following registry key using regedit.exe: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\aeDebug Additional notes on CrashGuard ============================== Disabling CrashGuard's Crash-Protection --------------------------------------- If you turn-off CrashGuard during a session, CrashGuard may continue to provide protection to some programs which have already encountered errors which it handled. Programs which have experienced no errors will not receive crash protection after CrashGuard is disabled. When does CrashGuard not catch a crash? --------------------------------------- Although CrashGuard catches every type of crash, it can not catch all crashes that occur in KERNEL32.DLL, VXDs, and certain device drivers. When does CrashGuard not fix a crash? ------------------------------------- CrashGuard tries to fix every crash it intercepts, but it isn't always successful. Situations where a "recovery" may not be possible are: - the application crashes after it has corrupted its data - the application has entered a state and can not continue until the state is cleared - the application is 16-bit and has destroyed its stack When does Anti-Freeze not work? ------------------------------- As when fixing 32-bit crashes, Anti-Freeze can not help an application if: - it froze after corrupting its own data - it is waiting for a state that was never cleared - it is a 16-bit application that stopped processing messages How much memory does CrashGuard take? ------------------------------------- CrashGuard is designed to be very transparent and lean. The 32-bit exception handler takes no memory when "idle," and about 100K when handling a fault. The 16-bit exception handler uses 40K. The application associated with the icon in the clock area uses 44K. The ctrl-alt-del feature, when enabled, uses 40k. - Grand total: 124K How safe is CrashGuard? ----------------------- CrashGuard is extremely safe. As a "JIT (just-in-time) debugger," the 32-bit exception handler is only called when an exception occurs, so at worst, it can only crash an already-crashed application. The 16-bit exception handler is also very safe in that it performs no background activity, does not hook, and does not subclass it is only called by Toolhelp (part of Windows) when a crash occurs in a 16-bit application. The application associated with the icon in the clock area does nothing but bring up a menu when it is selected.