Filtering system keys

There are a number of special keys that are used by the operating system for various purposes. In general it is not possible to use KeyboardTest to test these keys. By checking ‘Filter Systems Keys’ box some special purpose keys will be disabled for the duration of the test. Exactly which keys are disabled will depend on your keyboard and which version of Windows you are running

Windows NT4 / 2000 / XP

The normal function of the Print screen key and the left and right windows keys will be disabled and these keys can then be tested in KeyboardTest. With the filter running only the Power key will not be testable.

Windows 95 / 98 / ME

Due to limitations in the Window95/98 operating system it is not possible to circumnavigate the functioning of the keys used for operating system functions. These are.

•	The Print Screen key

•	Power control keys (Sleep and Power)

•	The up stroke of the Windows keys. (Note that the down stroke is captured however)

Using the ‘Filter Systems Keys’ option will disable the following Key combinations. CTRL-ESC, ALT-TAB and the normal function of the Windows keys.

Notes

Filtering can be enabled automatically at startup by using the ‘/f’ command line parameters.