OK, I'll try my best to explain in absolute english
When you click a link or type address into your browser a few things happen,
1) your broswer takes the address and initalli does a Domain Name service lookup(DNS), this takes teh domain name (
www.accringtonweb.com) and translates it into an IP address(PCs don't understand text remember)
2) your browser then makes a request to the IP address that has been returned, passing the extra bits of the URL(/private/main.cfm? etc)
3) to cut it short teh browser returns the web page as text (HTML)
The problem is that if your DNS is failing (BTW , this is a ISP issue) your access to teh internet will be sporadic at best. As you have found some sites work, other don't. You can try putting another ISPs DNS servers in your internet settings. I can give you details of this but it is a bit 'involved' for a webpage