A couple of my sites don't open normally but from different PC or thorugh proxy site. Is it because of virus. I remember it happened before and a guy made it right for me using team viewer. It was something related to DNS redirect or something like that. Can anyone help?
Do they work only from certain proxies? Was DNS changed? It could be IP ban? Have you contacted your host yet?
Check your .htaccess files for suspicious redirects and make sure you are scrolling all the way to the end of the .htaccess file because hackers sometimes add 100s blank lines, then add their code and 'tab' the code over to the right, then add another 100 blank lines.
You could try changing your DNS to google's public DNS; there's a guide on how to do that here: developers.google.com/speed/public-dns/docs/using - hope this helps!
1st check if you have DNS settings correct for your domain or not by using the following URL http://intodns.com/ If you have any error message than contact the hosting provider and ask them to correct the DNS zones for your domain because basically DNS is responsible for your domain to resolve it worldwide.
Why not you are using your server provider DNS for your domain? you can contact the hosting provider or server provider and ask them to configure the nameserver correctly to resolve the issue permanently ....