Internet explorer won't connect to the internet. I know that the connection is fine as Firefox works. I have cable broadband through a wireless connection. When I try to use Explorer it comes up with Internet explorer annot display the webpage. I have tried to look at other threads but can't seem to fix the problem. I need access to IE due to updates etc. Any help would be grateful as I seem to be going round in cirles.

Check your connection settings as you might of check Use Proxy and not set it up.
Tools > Internet Options > Connections tab > LAN Settings > UNcheck everything.

I've tried that and it doesn't change anything. I've also tried resetting the setting in explorer, downloaded a new version just in case but nothing has worked so far.

Any changes that either happened or that you perhaps made to your computer around the time that the problem started; particularly any software or hardware that you installed or setup.

When was last time worked?

Have you tried system restore back to when there was not a problem?

Go down till you see
How to use System Restore to restore Windows XP to a previous state
How to restore Windows XP to a previous state (http://support.microsoft.com/kb/306084)

Choose a date when there was not a problem

There have been no changes in terms of software, but I don't think that explorer has worked since we changed our internet provider to Virgin Cable. There doesn't seem to be a restore date before that point. The system I have is running Vista and don't know if this is causing a conflict. Also I did try to run PCgaurd the free antivirus from virgin, which blocked most of my access to the internet. Which I have since deleted and installed F-secure. Looking at my system restore dates the only other event is the service pack 1 for vista.

Did it work prior to SP1 installation?

As you have mentioned that no SW changes, I would try to use the system restore date closest to the date after SP1 was installed.

You mention that you deleted PCguard, did you uninstall it and not just delete the folder?

I would also recommnend using a registry optimizer/cleaner

ccleaner (Freeware)
Download CCleaner 2.13.720 - FileHippo.com (http://www.filehippo.com/download_ccleaner/)
On the right hand side, click download latest version

Try these, this may not solve issue but will hopefully get closer to helping out