Strange name.  Microsoft Security Essentials.  A very easy to use antivirus…install it and it does it’s thing.  It’s free, and requires no registration.  It remains to be seen if it will be as good as Avast and other AV programs.  I’ve been using it on a couple of computers for a few months and it seems to be good.

Main Site: http://www.microsoft.com/Security_Essentials/

Good free antivirus.  I’ve used it for years without any problems.  The interface is a bit more complex than it probably should be.  You must register once per year (free).

Main site: http://www.avast.com/

Download: http://www.avast.com/eng/download-avast-home.html

Register: http://www.avast.com/eng/home-registration.php

Excellent alternative to the built in defrag software.  Big benefit for Windows XP users, Windows 7 built in defrag isn’t too bad.  Simple to install and use.  Can schedule a defragment.

Main site: http://www.piriform.com/defraggler

Download: http://www.piriform.com/defraggler/download/standard

Now known as ccleaner.  Does a great job removing temporary files and cleaning up the registry.  Completely free.  Removes the crap that builds up on your computer.

Tip:  Set it up to run at startup.

Main site:  http://www.ccleaner.com/

Download:  http://www.ccleaner.com/download/downloading