WHEN I AM PLAYING A AVI OR OTHER VIDEO FILE WHILE USING MPCSTAR I CANNOT REMOVE THE SUBTITLES. APPARENTLY,IMBEDDED IN THE VIDEO FILE. I CANNOT OPEN THE SUBTITLE PANEL IF THEY ARE IMBEDDED SUBTITLES WITHIN THE AVI FILE. 
Well, you can’t unless you’d like to lose parts of the video itself.
Those subtitles are what we call hardcoded, which means that whomever encoded those subtitles had them put onto the video frame. That’s why most rippers use soft-subtitles. These are the ones you can change and turn off.
So, either;
A) Learn to live with it
B) Sacrifice that part of the video by altering it, or choose to cut it out (crop it)
C) Delete the video and find another release, one preferably with soft-subtitles
Those are your only options in this case.