I use PC Tools Firewall Plus which has worked in its default settings for some years. In the past 48hours it has suddenly started to play up in that it will allow access to all sites in the 'normal' mode but will only allow access to MS Updates and some other MS sites if it is downgraded to 'Allow' mode.
Has anyone any experience of problems of this nature or can provide suggestions as to the cause?
I had update problems a few months ago with PCTools firewall and W7. I got rid of it and switched to the W7 firewall on advice from forum members - so far, so good. I have checked and found my PC is "invisible".
Problem with the Windows firewall is that I am running XP Pro SP3 which has a limited Windows firewall.
Everything has been fine for well over a year and even after the last updates all was well. The only difficulty recently was with .NET Framework which became corrupt (again) and needed a complete reinstall. The corruption of .NET Framework has occurred before and re-installation has never caused a problem like this.
PC Tools Firewall automatically shuts the Windows firewall down on installation so I doubt there is any interaction as it is not possible to start the Windows firewall with the other installed.
To prove it was the firewall that was the cause of my problems, I uninstalled it and started the Windows firewall. All now works as advertised as far as site connectivity is concerned; hopefully it will resolve the situation until I can find what the cause was.