err connection reset

I still have Error connection reset it only seems to happen on my computer i checked antivirus and i'm 
using this ethernet adapter called "Ultra" i tried many things such as Cmd commands and others it still doesn't work please help. I also noticed that my skype disconnects sometimes and reconnects after 2 mins and this happens a lot. Could it still be an ISP problem? I also reset my router and etc still doesn't work.