By default on a Windows XP pressing the Shift Key 5 times in a row turns on StickyKeys and brings up the warning dialog. In normal operation this doesn’t happen very often, but if you’re bashing someone with your rifle in Call of Duty it can pull you out of the game to show this dialog.
Normally you click on the proffered Settings button on the warning dialog and you can disable this feature. However on some configurations clicking on the Settings button does nothing. This happens when the Accessibility Options control panel applet (Access.cpl) is not installed as this is where the StickyKeys settings are.
To fix it insert a Windows XP CD into the drive (D: in this example) and enter the following command at a command prompt.
The “Accessibility Options” applet will now be visible in Control panel and the StickyKeys settings will appear as they should. To disable the dialog coming up untick the “Use shortcut” box on the “Settings for StickyKeys” dialog.