Zitat von
MSDN:
dwFlags
[in] Specifies various aspects of function operation. This parameter can be one or more of the following values.
KEYEVENTF_EXTENDEDKEY
If specified, the scan code was preceded by a prefix byte having the value 0xE0 (224).
KEYEVENTF_KEYUP
If specified, the key is being released. If not specified, the key is being depressed.
Und für dwExtraInfo probier mal einfach 0