Hello Carol,
Kaspersky has a very good reputation as far as anti virus software is concerned. They don’t seem to get anywhere near the level of flack that is thrown at the other two you mentioned. Whether you need any other security software would depend on the particular version you have and whether it has firewall and spyware protection as well as anti virus.
If it is just basic antivirus then you probably have the standard Windows Firewall running that you can continue to use. I’m not sure how good that is in Windows 7 but there’s always the opportunity to change to something like Zone Alarm if you wish to. Here’s a Kaspersky version comparison
http://www.kaspersky.com/compare and here’s a review of the full ‘Internet Security’ version.
http://www.pcadvisor.co.uk/reviews/inde ... wID=117094
If it doesn’t include anti spyware, or even if it does, a couple of programs such as MalwareBytes and Spyware Terminator may be useful, not necessarily to run continuously, but to do the occasional scan. I don’t think Kaspersky has a free version. Once the trial runs out you can either choose to subscribe or switch to one of the free AVs such as Avast or AVG. Most of the software I’ve mentioned should be available here
http://www.snapfiles.com/ or from your favourite download site.
Happy Toshibaring,
Alan