While no computer is totally secure you are on the right path here are a few more suggestions for you.
1. Use spyware blaster...it's free.
http://www.javacoolsoftware.com/spywareblaster.html
Enable protection for all!
2. Use a firewall that will block outgoing connections as well as incomming!
You can find free ones in the sticky in this section!
3. Enable your tea timer on spybot sd to monitor any unwanted registry changes and also imunize your PC in spybots settings.
4. Always keep all of these programs up to date, after you update spyware blaster click on the enable protection for all.
5. After you update spybot always click on the imunize button.
6. Check for updates everyday on all these programs and turn on automatic updates for windows.
7. Never download anything you are not sure about or open email attachments that you are not sure about.
8. Run a full system scan at least once a week with all your anti malware programs, I will usually scan with one program once a day. Spybot one day, ad-aware the next day ect ect...!
9. Download firefox or opera browser and use it instead of internet explorer as they are more secure than internet explorer. Keep internet explorer though incase you have to use it, for an example a web page does not display right with firefox. This is getting to be kind of a rare situation now days but it still happens once in a while.
