It would be appreciated if someone has any suggestions.
Well, inevitably, the first one has to be: please give us a lot more details.
First, about your computer (see this post for the information we really need).
Then please describe your workflow, step by step. It is very unclear what you mean when you write you save a video after recording it. It decreases the sound quality of the video.
Third, please tell us rather more about the actual video files you are using. The free MediaInfo utility will tell you (and us) a lot of information about the codecs used to create and play them). This tutorial will take you through the steps to find this information.
Finally (I think), please tell us rather more about what you are recording. VSCL is normally used to "clean up" existing audio in a video, not usually to record that audio.