very strange connection problems

[#1]

Now this may be a sign that I'm going mad but can anyone explain why I am able to get onto the internet and view certain sites such as plus.net of course and others such as bbc.co.uk and skysports.com but I can't get onto the AVG.com website.
I'm desperately trying to install AVG but I am getting a message at the start of installation saying I already have an antivirus running on this pc and that I should uninstall it.
As far as I am aware I've uninstalled AVG and there is nothing else on here (I've checked in uninstall progs...)
I have tried to download the AVG uninstaller on their website (as advised in another thread) but I can't get on there.
What is happening?
I have to say that this PC was playing up a bit and I have used the F5 facility to load the last know working configuration.
Can someone please get me out of this sticky yet challenging mess, thanks

[#2]

You could try this

Quote

Is There an Uninstall Utility? Unfortunately, at this time Grisoft, the maker of AVG, does not have an uninstall utility for AVG. The recommended procedure is a time consuming one. You must download the latest version of AVG from the website, and then run it. 1) Click on the following link and download AVG to your desktop http://free.grisoft.com/doc/5390/us/frt/0 2) Double-click on the downloaded file to run it 3) AVG will present you with three options to choose from. Choose the Uninstall option to completely uninstall AVG Add/Remove Components - choose if you want to add/remove some components or reinstall the entire AVG program Repair installation - this option repairs or reinstalls missing or damaged components of AVG Uninstall - this option removes the AVG program from your PC 4) Once the uninstall has completed, restart your computer. You can then proceed to install another antivirus or install AVG again.