Moved from Total Protection Service which is an Enterprise product to SecurityCenter 10.
Can you indicate your operating system, service pack and how you connect to the internet plus what version of Internet Explorer is installed (regardless of whatever default browser that you may use) please?
Meanwhile try running the MCPR removal tool to get rid of all remnants of the old software and reboot before attempting a new download. See Useful Links at the top of this page.
Before downloading open Internet Explorer and go to Tools/Internet Options/Advanced and click Reset (assuming IE7, 8 or 9), Apply and OK.
Close and reopen IE and then go to Tools/Manage Add-ons and re-enable any add-ons you need.
Now try installing from the download page.
https://home.mcafee.com/Secure/Protected/Login.aspx (Make sure UK is your country setting at the top)