the problem am facing is like this:
i often plug in my bass into the mic-in jack and record it on audacity or the windows sound recorder and i often do this while there is a song or track playing along on the same computer on another software. now earlier it used to just record whatever was plugged into the mic-in (the bass) but now it records whatever is being played or say even if there is an error notification or anything its warning sound is also recorded.
even if i have nothing plugged in the mic-in jack and there is a song playing on youtube and i hit the record button on the windows sound recorder,nuendo, audacity, etc this stupid computer starts recording the sound from the youtube clip!

it never used to happen sometime back but now i cant fix it.
i have tried re-installing the sound driver and tried and re-installed many recording software, nothing fixed it. do you know how can i fix this?

any help would be awesome!