Remove the host from the network and run a full scan on the machine. In addition you can try the Norton Power Eraser:
https://security.symantec.com/nbrt/npe.aspx
If this does not resolve it than re-image the PC.
Symantec has a write-up here on it:
https://www.symantec.com/security_response/writeup.jsp?docid=2011-101915-4058-99&tabid=3