win7 and cse

CSE 2.5 this app dosnt like me ;D ive tried 3 times and installed and it stops any internet connection.
lastest firefox and thunderbird with comodo firewall and antivirus. on a cable broadband “virginmedia” via broadband router and wireless router?
as for getting certificate, i tried using internet explorer but that came back with an error about certificates? when i try to get a cert via the install procedure it tells me ive already got one and have to get on to support if i want a new one ???
Im not the greatest when it comes to apps but this is driving me mad :o will have to go back to mailwasher for the time being