Lol, thats asked so many times, we could make a faq like that:
Q: How can i make a review for any game? I would like to record my voice, and the game's sounds as well.
A: Its simple.
Go to the voice control panel (run/sndvol32, or search for it in the start menu)
Choose properties, check the "for recording" radio button, then check the microphone and WhatUHear/stereo mix (it depends on the sound card type) checkboxes.
Press ok.
In that recording dialog, search for the stereo mix/whatUHear or whatever, and check the select checkbox which located nearby.
Now, properties again, but for playback.
Uncheck the mute checkbox near the microphone control, and if everything is right, you should hear yourself when you're talking, plus the speaker sounds, same for recording.
If you would like to set it back, simply go back to the preferences, check 'for recording', press ok, and check the select checkbox near the microphone control.