Help with Audio interference requested

Hello there, I wonder if anyone can help. I have noticed that without muting the microphone settings entirely I get awful interference. I am using a G41M combo board and running the audio through the in built audio via the rear MB ports. All sound through the ports is fine when using headphones etc and mic is fine with skype and also line in when defaulted to headphone setting but some sort of sounds interference is happening as soon as I unmute in Sound section of Control Panel/Sound/Playback/Speakers/Properties/Levels/Microphone.Its worse when running a game I guess it might be GFX card interference or driver issue or connection prob but it has been something I have ignored but think needs resolving.

Help appreciated and many thanks in advance. Can provide full info if needed. Running Gigabyte Board 2.07 Bios I think and W7.
Basics here

DUDE-PC
Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7600) (7600.win7_gdr.130318-1532)
Language: English (Regional Setting: English)
System Manufacturer: Gigabyte Technology Co., Ltd.
System Model: G41M-Combo
BIOS: Award Modular BIOS v6.00PG
Processor: Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz (4 CPUs), ~2.4GHz
Memory: 8192MB RAM
Available OS Memory: 8190MB RAM
Page File: 2671MB used, 25992MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: 96 DPI (100 percent)
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
DxDiag Version: 6.01.7600.16385 64bit Unicode

Sorry for the mess thanks folks