I don't know whether this is the right place to write which i apologize for
Now the problem - I'm using audacity to record some bass stuff [melodies and demos mainly].However, when i try to record something a nasty whistling sound occurs and when i try to record louder, the sound gets louder as well.I tried another program - the same happened.Then reinstalled my sound card drivers but the problem didn't go away.I recently changed my motherboard and my graphics card but I hope the problem is somewhere else.Thanks in advance - I hope you could help me
Try turning the pots on your bass down.

Check you don't have any strange options on your soundcard enabled, open up sound manager from the control panel a lot have "noise removal" which is terrible.
I still have the noise while recording.I tried everything I could think of but unfortunately there's no success.When I play old recordings they are ok.I also tried to record both plugging the bass directly into the computer, and through a microphone - the same.