Turned PC on tonight and suddenly my mouse makes sound...

After doing nothing to my computer, since today when I turned it on, the sound in my headphones chance according to what my PC is doing:

Moving mouse: High-Pitched sound
Scroll wheel: Cracking sound
Starting MW:O or sth which needs a lot of CPU: Horrible loud sounds, altough I still hear the original sounds (voice, sound fx)

I do NOT have an onboard sound-chip, I have a Sound Blaster X-Fi with custom drivers. Everything was working normally until today. No patches, updates or anything.

Until I know what to do I can't play.

Update: Even I turn OFF the sound on the PC (mute) the sounds are still there.

 

What kind of mouse are you using, does it use a USB connector? And if it does have you tried using it in different USB ports?

 

I am using a Logitech g400 and plugging the mouse off, also did not help. I changed USB ports and didnt help eighter.

When I open a browser window or anything that makes the PC "work" it gets louder then again a bit more quiet. It HAS to be some kind of interference...