.h seems to up set windows on every PC I own Keypad .h is not recognsed

Windows 7 Arduino was working up to wanting to include #include keypad .h keypad.h is not recognised no such file yet it has been down loaded!

Liamthe1st:
Windows 7 Arduino was working up to wanting to include #include keypad .h keypad.h is not recognised no such file yet it has been down loaded!
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yet it has been down loaded!

Where did you put it and did you stop and restart the IDE after installing the library ?