DO I HAVE A VIRUS OR ARE THESE "NORMAL" ERROR LOG WARNINGS?????

I bought a refurbished Dell PC directly from Dell for my Home PC. It came with Microsoft Office Small Business Edition 2003 already loaded, running Windows XP Home. I dont have a small business nor do I connect with any other computers at my house. We also have Norton 2004. My husband thinks that someone is tapped into our computer or something because when we look in the security logs, there are a number of applications being launched at random times and days that neither of us have authorized or been asked to run. Also we only created 2 Users, one for me and one for him, we are both "Admin" type of users, but in the error logs and security logs it says things like "......is not authorized on the local policy, please check with your administrator" "......attempted to access remote ....." We dont login anywhere from a remote computer.... Are there applications in MS Small Business that are automatically launched (networking apps, wireless app's, etc.) because it is geared towards Small Business's? If so, what commands, or local policy rules, etc. are the default one's, and should we not be using this edition if we are worried about which "system" activities are ACTUALLY VALID versus if we have a virus which makes things that aren't standard appear as though it the system? I hope this makes sense, please help if you can, even if there is a website that goes into detail about what ACTUALLY is an "automatic" application, or why in the computer mgmt are some things "stopped", "automatic", or "manual", when I didnt ever create any policies....