Most people here use the Windows tool on its default schedule of weekly.
Some use other defraggers like Auslogics.
The choice is more a matter of how obsessive you are rather than on demonstrable differences in PC performance.
I use Win 7 defragger and have never done a manual defrag. My fragmentation levels vary from time to time, but are rarely above 5%.
I fully agree with Ignatzatonic on using the Windows defragger. Third party ones will defrag but not in an optimum way for windows 7.
On all of my computer i have ever had i have used AVG free edition and have been virus free :) I also use ad-aware-SE i think it is and that gets rid of malware i also have used the free edition of that and that has kept me from getting malware :)
AVG and Adaware are a generation or two behind in the preference of those here who have been with Win7 since beta, as is Spybot.
The new-generation freeware that is in favor now is MSE, Avast6, Malwarebytes and SuperAntiSpyware.
Quote