you proceed to type another non-modifier key before you let go of Alt
and Shift, the Alt and Shift act as modifiers in the usual way. A
more permanent work around is to change it to another key combination,
-or disable it in the keyboard control panel.
+or disable it in the "Regional and Language Options" applet of the
+Control Panel. (The exact sequence of mouse clicks in the "Regional
+and Language Options" applet needed to find the key combination that
+changes the keyboard layout depends on your Windows version; for XP,
+in the Languages tab, click "Details" and then "Key Settings".)
** Cygwin build of Emacs hangs after rebasing Cygwin DLLs