Internet access problems after installing IE8

Hello,

Running Windows XP on my desktop with IE6 SP2.

Installed IE8 after being propmpted whilst surfing so I installed thinking its a free upgrade for IE6 to IE8.

IE8 seemed to install successfully. Once restarted pc could NOT access any web pages (Page cannot be displayed) error everytime. Uninstalled IE8 and successfully went back to IE6. Still same error when attempting to access web pages.

Contacted my ISP (Tiscali) who checked things from their site and said not a modem problem (Broadband).

Tried installing Tiscali s/w again but still no joy.

PLEASE can anyone help as use net everyday

Thank you !!