Microphone is not recording

I tried using my headset, but the mic don't work on my pc. I still can use the headphones. So I still ear everything. When I Skype(not only skype), the other person ears sometimes my system sound(music etc.). When I plugin my headset, my pc recognize that I plugged in a mic. I don't use my headphone often and the last time it worked fine.

What I tried already:

I installed the realtek drivers multiple times.

I followed this guide and this one.

I used the headset on a other pc. it worked fine!

I bought a usb soundcard. Microphone is not working!

I scanned my pc for malware with: Combofix, Malwarebytes, hijackthis, AdwCleaner, Junkware Removal Tool and 360 total security.

I ran windows 10 in a vm virtualbox and tried to skype(Hahahaha )


I'm getting really desperate.
Does somebody else has an idea how I can fix this?



**System Information**

OS: Windows 7 Professional 64-bit (6.1, Build 7601) Service Pack 1

CPU: AMD FX(tm)-4100 Quad-Core Processor

Memory: 4096MB RAM

Asrock 970 Extreme 3 (onboard audio)

grfx: amd 7770


**Sound Devices**

Description: Luidsprekers (Realtek High Definition Audio)

Default Sound Playback: Yes

Default Voice Playback: Yes

Hardware ID: HDAUDIO\FUNC_01&VEN_10EC&DEV_0892&SUBSYS_18497892&REV_1003

Manufacturer ID: 1

Product ID: 100

Type: WDM

Driver Name: RTKVHD64.sys

Driver Version: 6.00.0001.7487 (English)

Driver Attributes: Final Retail

WHQL Logo'd: Yes

Date and Size: 4/14/2015 19:38:14, 4664792 bytes

Other Files:
Driver Provider: Realtek Semiconductor Corp.

HW Accel Level: Basic

Cap Flags: 0xF1F

Min/Max Sample Rate: 100, 200000

Static/Strm HW Mix Bufs: 1, 0

Static/Strm HW 3D Bufs: 0, 0

HW Memory: 0

Voice Management: No

EAX(tm) 2.0 Listen/Src: No, No

I3DL2(tm) Listen/Src: No, No

Sensaura(tm) ZoomFX(tm): No

**Sound Capture Devices**

Description: Microfoon (Realtek High Definition Audio)

Default Sound Capture: Yes

Default Voice Capture: Yes

Driver Name: RTKVHD64.sys

Driver Version: 6.00.0001.7487 (English)

Driver Attributes: Final Retail

Date and Size: 4/14/2015 19:38:14, 4664792 bytes

Cap Flags: 0x1

Format Flags: 0xFFFFF

Edit: I posted it in the wrong sub forum I think.