[color:"orange"]my default output device is 'Realtak HD Audio Output'[/color]
Can you change that to something else? AFAIK (have not been paying attention recent developments in sound card technology) Realtek only makes chips for onboard sound. If you have onboard sound enabled and have a separate sound card, that could be part of the problem (at least for PC generated sounds).
If your audio connectors are on the back of the computer, onboard sound will probably be arranged vertically (mid to high on the case, near one side) with a bunch of other connectors, while a separate soundcard will most likely be horizontal (and lower).
The initial description sounded like your microphone was simply much more sensitive than your friend's, but unplugging it eliminates that possibility.
[color:"orange"]I tried voicechat with someone, started my music player and the other person was able to hear, he also heard me typing on my keyboard(it makes some noise) yet when I said something he didn't hear that.[/color]
Some monitors (and possibly keyboards) have built-in microphones, but they would likely be visible even if they were not labeled.
There are programs, and possibly options under Windows accessibility features, to make a sound on each key press. That may have been what your friend heard, or there is a microphone close to the keyboard that could pick up the sound of physically hitting the keys, but was not sensitive enough to pick your voice. If your friend can tell the difference between hitting a key normally and hitting it hard, then the sound is not from a program or accessibility feature.
