Charles Patterson,
Prior to installing OneCare, disabling existing antivirus programs is recommended because it may interfere with the installation and function of OneCare. You can install OneCare one of two ways, via internet download or CD installation. The CD installation will install the version which is on the package.
Download OneCare from http://onecare.live.com/site/en-us/center/download.htm for the latest version of OneCare. The OneCare installation defaults to a trial version and at the end of the trial can be converted to a full version by means of purchasing the product and creating a live ID to activate the product. Thank you for visiting the OneCare forum,
I hope this helps,
Lori MS