Are you still able to type in the URLs to other websites an visit them normally, or is access to every website blocked within Firefox? Changing ISPs normally wouldn't cause such an issues, though related factors could include:
1.) ISP-supplied parental control software. Try disabling it and restarting your computer if it's installed.
2.) Modem configuration. Are you using the same modem or a new one, and have you customized or reset the configurations?
3.) Login requirement. Does your ISP require you to log into the service with a username/password before you can connect?
Let us know.
I have recently changed isp. Have been using firefox as my browser for a few years now. After changing isp firefox will no longer work. Only IE. Following keeps coming up:
Access denied to system because of URL Filter Configuration.
Your system was configured to deny access to the requested URL.
Possible Problem Cause
Request denied, as specified in the local filter list configuration.
Contact your network support team if this problem persists.
Have contacted isp. Cannot help. Use avast and avg free. Windows firewall.
At a loss and no one else seems to know either. Suggestions greatly appreciated.