Lenovo Hotkey Driver - Windows 7
Laverne Levenstein
If you want 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 more information, 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 a REG_DWORD value of 0x01.
With USB keyboards, you must enable the keyboard-initiated crash in the registry. In the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\kbdhid\Parameters, create a value named CrashOnCtrlScroll, and set it equal to a REG_DWORD value of 0x01.
With Hyper-V keyboards, you must enable the keyboard-initiated crash in the registry. In the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\hyperkbd\Parameters, create a value named CrashOnCtrlScroll, and set it equal to a REG_DWORD value of 0x01.
Some laptops use the PS/2 driver for the built-in keyboard and also support external HID keyboards. For these systems, consider creating both the USB and PS/2 registry keys to allow the use of either keyboard.
The Dump1Keys registry value is a bit map of the first hotkey to use. For example, instead of using the rightmost CTRL key to initiate the hotkey sequence, you can set the first hotkey to be the leftmost SHIFT key.
You can assign Dump1Keys a value that enables one or more keys as the first key used in the keyboard shortcut sequence. For example, assign Dump1Keys a value of 0x11 to define both the rightmost and leftmost SHIFT keys as the first key in the keyboard shortcut sequence.
Example: In this scenario, a laptop uses a PS2 keyboard driver, and an external HID keyboard is attached. Setting both values provides the ability to trigger a manual system crash from either keyboard. A manual system crash can be forced by holding the rightmost control key and pressing the spacebar twice when the following registry key is set.
It's possible but rare for a system to freeze in such a way that the keyboard shortcut sequence doesn't work. Using the keyboard shortcut sequence to initiate a crash will work even in many instances where CTRL+ALT+DELETE doesn't work.
Forcing a system crash from the keyboard doesn't work if the computer stops responding at a high interrupt request level (IRQL). This limitation exists because the Kbdhid.sys driver, which allows the memory dump process to run, operates at a lower IRQL than the i8042prt.sys driver.