So I reinstalled Guitar Pro 5 yesterday and it worked fine. I composed a song and went to bed and today I can't hear the notes when I'm writing tabs in the program. I can hear what I've written when I press play but not when I'm editing a note which is a pain for me because I really don't have a clue about what I'm writing unless I can hear it at the same time. Little help?
hey, thats happened to me before
i dunno, something dumb happens with the program, and you probably need to go to: options - preferences, and then check the box that says, "playback during editing"

that way... well... it plays back during editing
Go to "sounds and audio devices" in control panel and then press "advanced" on the "volume" tab. Then check to see if the "MIDI" volume is turned up, if not then turn it up and your problem should be solved.
HoldYourColour gave the answer but thanks to all of you. You guys are the best ^^ now I can get back to writing my Monkey Island inspired music.