My existing version was due to expire, so I bought the 2011 version as I liked the product and had used it for the last 2 years.
Sadly, after using Webroot's own uninstall program prior to installing the 2011 version, I have been unable to use the 2011 version.
Like another reviewer, when I tried to install the 2011 program I kept getting the message: "a necessary file could not be located, setup cannot continue."
I rang Webroot's UK helpdesk and they said they would e-mail me a couple of programs to run that would clear up the problem. The problem arose, he said, because some elements of the old program hadn't been removed by the uninstall program. I duly ran the programs he sent but the problem remained. I then checked the FAQ section on the Webroot website and found a page devoted to the problem. I then tried every avenue they suggested, including rebooting in Safe Mode and running the clean-up software that way. The problem still remained.
I e-mailed Webroot again and asked for further advice. I am still waiting, a week later.
So if you plan to buy this product to renew your subscription, I recommend you don't bother. It's just not worth the hassle, or the lost money on a product you can't use.