For those of you running Win 7, you may have found it frustrating finding a suitable anti-virus product. From experience, major players promoting Win 7 compatibility have proven anything but.
A friend told me about Microsoft's new Security Essentials, which handles anti-virus, spyware and malware detection. Best of all, it's free! You can download it here:
Unlike other products, Security Essentials has a remarkably small footprint and has negligible impact on performance. Highly recommended.