Custom Key Filter Configuration (Standard 7 SP1)


Custom key filters let you add your own key filters to meet any special requirements that you may have that are not included in the predefined key filters.

You must use the following format to create custom key filters:

  • General formatting rules: Filters must be expressed as zero or more modifier keys and a character, number, function, or cursor key, delimited by a plus symbol.
  • Modifier keys: Ctrl, Alt, Shift, and Windows. Left or right can be specified including LCtrl, RCtrl, LAlt, RAlt, LShift, RShift, LWindows and RWindows.
    These are not case sensitive.
    Modifier keys are not supported as a standalone or final key in a custom key filter; instead, use a predefined key filter to block modifier keys.
    For certain keys, for example, PrintScrn, ScrollLock, and Break, one-sided modifier keys will not work. Use the generic modifier instead; for example, use Alt instead of RAlt.
  • Character and number keys: Any key from A through Z and 0 through 9; and any other symbols that are supported by the keyboard.
    When applying a custom key filter to block an uppercase letter, the policy setting must be Shift+<letter>. For example, setting H as a custom key filter only blocks lowercase h. To block the uppercase H, use Shift+h.
    If you want to filter numbers, you must also filter the corresponding cursor key to filter them on the NumPad. For example, if you want to block the 8 key, you must also filter the Up key. At this time, you cannot block the 5 key on the NumPad.
    If you filter navigation keys on the NumPad (Up, Down, Left, Right, Home, End, Page Up, Page Down), the corresponding number will be blocked on the NumPad. The number on the number row above the letters will still work as expected.
  • Function keys: Any "F" key from F1 through F24. May also include CapsLock, PrintScrn, ScrollLock, Break, Tab, Space, Esc, and Backspace.
    No spaces are allowed in the names and names are not case sensitive.
  • Cursor keys: Up, Down, Left, and Right (arrow keys); PageUp, PageDown, Insert, Delete, Home, and End.
    These also do not have spaces in their names and are not case sensitive.
    When blocking cursor keys (Left, Right, Up, Down, and so on), you may want to add a key filter to block them with modifiers as well. For example, when blocking the Left cursor key, also add a filter for Shift+Left. Otherwise, the Shift+Left key combination may circumvent the Left key filter.

For example, the following list shows some custom key filters:

  • Windows+L
  • LWindows+L
  • Ctrl+Break
  • Shift+Ctrl+Esc
  • Ctrl+C
  • Ctrl+Enter

Use the following steps to configure custom key filters:

  1. From the Start menu, click Run, type Gpedit.msc, and then click OK to open the Local Group Policy Editor.
  2. In the console tree, browse to Keyboard Filter by using this path: Computer Configuration\Administrative Templates\System\Keyboard Filter.
  3. In the details pane of the Local Group Policy Editor, select Custom Key Filters, and then click Edit Policy Setting; or right-click Custom Key Filters and then click Edit.
  4. In the Custom Key Filters dialog box, click the Enabled option to enable custom key filters.
  5. In the Options text box, click Show.
  6. In the Show Contents dialog box, in the text area under the Value column, add a new custom filter or modify an existing custom filter by using the format previously specified in this topic.
  7. Click OK to save the custom key filter and close the Show Contents dialog box.
  8. Optional: In the Comment text box, add a description or explanatory text to document your custom key filter.
  9. Click OK to save your changes and close the Custom Key Filters dialog box.