file sharing driving me nuts

When i bought my mbr 2 months ago, i was playing around with the settings and i allowed file sharing between my windows Pc and macbook, but later i decided to see if i can stop the two computers from seeing each other's activities and nothing has worked. I disabled bluetooth just so they don't see each other, but still everything i do on windows Pc still is seen in my macbook and vice versa.

I have also been to the Sharing folder on my macbook to see if i can locate the windows ID, but can't seem to find it. Interestingly however, i see it in the Finder, but then there is no where to disable it or remove it completely. Please help, as I remember accidentally allowing an unknown computer to share my files at the same time i allowed my Windows Pc and although i no longer see that random PC on my macbook anymore, i am concerned that maybe my acitivites are still being seen by whoever owns that PC.

Can someone pls tell me how to permanently find and disable a shared PC on my macbook pro. Will greatly appreciate an effective help.