Sam2259,
Does the time on your desktop match the time set in your bios? Were you running multiple antivirus/antispyware programs on your system before you installed OneCare? If so which ones did you run? Could you run a complete scan at http://safety.live.com not a quick scan, a complete scan.
I've noticed several users having this issue and am trying to analyze this free trial timer issue.
Note: Bios troubleshooting is intended for advanced users only. Do not attempt if you are not an advanced user.
Rick, MS