Just wonder if you use any type of file sharing software which often is an invitation to allow spam to infiltrate a computer with unwanted things.
I recommend you make sure you are up to date with all windows security updates and optional ones like Adobe or Java. It is also important to make sure Internet Explorer is up to date even if you choose to use another browser such as Chrome or Firefox because McAfee relies on an updated IE to function properly.
If you are experiencing any issues with programs not functioning properly look at some of the Anti-Spyware/Malware & Hijacker Tools that will assist you getting things cleaned up.
It is unfortunate that we all get spam from time to time but be careful and keep practicing what you mentioned in your opening post.
McAfee Volunteer Moderator
Moved to Malware Discussion > Home User Assistance.