Well I have finally found what was conflicting with avast and stopping me getting to my isp homepage unless I used https to get there, plus about 3 other websites I came across in the past few weeks, after uninstalling different software to try and find out the problem it turned out to be Internet download manager which I have been using for years along side avast but for some reason this version of avast didn't like this version of idm. This version of Idm worked fine with a different virus scanner. So now I either ditch Avast or idm or wait for updates from avast or idm to see if they will play nice together again. Either way I can sleep at night again now lol
Once again thanks for all of the help I had trying to solve this issue.