Are you using a different dns setting for that comp? Like maybe you are being filtered through mcfeces due to isp or other malware crap?
try 8.8.8.8 or 1.1.1.1
I guess it's possible ... have switched to 8888 now and running a malware scan!
if changing the dns didn't resolve the issue then .. i dono wtf is going on .. it's one of the thing that would have persisted when you changed networks. Good luck !
