External C Headers

I'm trying (and failing) to create header files (and the respective .c files) for functions I may want to use in any project, eg: Generic.h and Generic.c for readInRange, readPositive, etc.

Let's admit I have the following file structure:
D:\MyFuncs\Generic.h
D:\MyFuncs\Generic.c
D:\MyProject\src\main.c

What do I have to do so that I can #include "Generic.h"?
I don't want to copy it to the project directory, because that would defeat the purpose of having a "functions database" for anything I might need: from simple printing or handling user input, to CRC calculations and USART serial comms for my AVR.

I'm using Code::Blocks on Windows 7, by the way.

But I just tried it with a header in K:/ an it worked perfectly.