Hey there ganster, welcome to Geeks To Go Forums.
Of course you cannot stay 100%, although you can try and prevent from getting infected. I would suggest downloading
Spybot Search & Destroy and running it every time you log off the internet. I would also suggest running your anti-virus once a week.
Always have your firewall on and never open any files that you do not recognize or know that you have not downloaded. This goes for e-mails too, dont open any attachments from any unknow e-mail address. Even when opening a file from a friend, be very cautious. If your friend has been infected with a virus, the virus might send the infection to all his addresses.
When learning in GTG U, I found prevention speeches that may be of use to you. Check it out:
The following is a list of tools and utilities that I like to suggest to people. This list is full of great tools and utilities to help you understand how you got infected and how to keep from getting infected again.
- Spybot Search & Destroy - Uber powerful tool which can search and annhilate nasties that make it onto your system. Now with an Immunize section that will help prevent future infections.
- AdAware - Another very powerful tool which searches and kills nasties that infect your system. AdAware and Spybot Search & Destroy compliment each other very well.
- SpywareBlaster - Great prevention tool to keep nasties from installing on your system.
- SpywareGuard - Works as a Spyware "Shield" to protect your computer from getting malware in the first place.
- IE-SpyAd - puts over 5000 sites in your restricted zone so you'll be protected when you visit innocent-looking sites that aren't actually innocent at all.
- CleanUP! - Cleans temporary files from IE and Windows, empties the recycle bin and more. Great tool to help speed up your computer and knock out those nasties that like to reside in the temp folders.
- Windows Updates - It is very important to make sure that both Internet Explorer and Windows are kept current with the latest critical security patches from Microsoft. To do this just start Internet Explorer and select Tools > Windows Update, and follow the online instructions from there.
- Google Toolbar - Free google toolbar that allows you to use the powerful Google search engine from the bar, but also blocks pop up windows.
- Trillian or Miranda-IM - These are Malware free Instant Messenger programs which allow you to connect to multiple IM services in one program! (AOL, Yahoo, ICQ, IRC, MSN)
To find out more information about how you got infected in the first place and some great guidelines to follow to prevent future infections you can read
this article by Tony Klein