Following is a way to make system crash from keyboard.
Thanks
Annie.
Forcing
a System Crash from the Keyboard
A system crash can be directly caused from most keyboards. In
Windows XP, this feature is available on i8042prt ports (PS/2
keyboards), while in Windows Vista and later, it is available on USB
keyboards as well. It can also be fully configured to accommodate
various keyboards using the registry key settings.
Two preparations must be made before this can be done:
- If you wish a crash dump file to be written, you must enable such
dump files, choose the path and file name, and select the size of the
dump file. For details, see Enabling
a Kernel-Mode Dump File.
- With PS/2 keyboards, you must enable the keyboard-initiated crash
in the registry. In the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\i8042prt\Parameters,
create a value named CrashOnCtrlScroll, and set it equal to
REG_DWORD 0x1 (or any nonzero value).
- With USB keyboards, you must set the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\kbdhid\Parameters
and create a value named CrashOnCtrlScroll, and set it equal to
REG_DWORD 0x1 (or any nonzero value).
Note There is a limitation with the Kbdhid.sys
driver that allows you to generate the memory dump process by using a
USB keyboard. The CTRL+SCROLL LOCK+SCROLL LOCK keyboard shortcut does
not work if the computer stops responding at a high interrupt request
level (IRQL). This limitation exists because the Kbdhid.sys
driver operates at a lower IRQL than the i8042prt.sys driver. For more
information on using this feature with the USB keyboards, refer to the
article 
Generate
a memory dump file by using the keyboard.
The system must be rebooted before these changes will take effect.
After this has been done, the keyboard crash can be initiated as
follows. Hold down the rightmost CTRL key, and press the
SCROLL LOCK key twice.
It is possible for a system to freeze in such a way that this
CTRL+SCROLL LOCK+SCROLL LOCK sequence will not work. However, this
should be a very rare occurrence. The CTRL+SCROLL LOCK+SCROLL LOCK
crash initiation will work even in many instances where CTRL+ALT+DELETE
does not work.
The system then calls KeBugCheck and issues bug
check 0xE2 (MANUALLY_INITIATED_CRASH). Unless crash dumps have been
disabled, a crash dump file is written at this point.
If a kernel debugger is attached to the frozen machine, the machine
will break into the kernel debugger after the crash dump file has been
written.
