Have you tried going into MSCONFIG and setting your system(s) to do a clean boot? Since things work in Safe Mode, I'd think it would be something in that startup list that's causing the problem.
A few of my programs are unable to communicate with their servers now and I can't figure out why as they were find two weeks ago and I haven't made any changes since then. The issue lies with a service/program within Windows as all the programs communicate fine in Safe Mode. Windows Firewall and ICS are both disabled within Services. Malwarebytes (my only AV right now) is disabled also.
I know this is an ongoing and repetitive subject but the numerous searches are all resulting in pointing fingers at an AV program, which I am sure is completely disabled. Any help is appreciated.