ServoTimer 2 Library

Hey I'm using Dev - C++ as my compiler and I wonder why when I modified the .cpp file by including Arduino.h went well. Twas alright all of a sudden. Then when I went home and use my computer, used the same program etc and the same modification, it says the same error again. Do you guys have any clue?

What error?

The error that I'm having is : C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:6:26: error: WConstants.h: No such file or directory C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp: In function 'void __vector_9()': C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:36: error: 'LOW' was not declared in this scope C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:36: error: 'digitalWrite' was not declared in this scope C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:43: error: 'HIGH' was not declared in this scope C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:43: error: 'digitalWrite' was not declared in this scope C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp: In member function 'uint8_t ServoTimer2::attach(int)': C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:66: error: 'OUTPUT' was not declared in this scope C:\Users\Kevin\Documents\Arduino\libraries\ServoTimer2\ServoTimer2.cpp:66: error: 'pinMode' was not declared in this scope

I have changed the .cpp file, made sure that it was also in the right library folder.

Replace the line:
#include <WConstants.h>
with the line:
#include <Arduino.h>

I did replace it at first and it didnt work at home. Then I tried to replace it again at school it work. Went back home to do it. It gave me the same error again. Very weird I dont whats the problem.