Below is a list of FREE software that I have found very useful.

The programs below are absolutely free (not shareware, but freeware).  There are some excellent utilities that make your computing life a lot easier.  Many of the programs come from one of my favorite free software sites: Snapfiles.com http://www.snapfiles.com/freeware/

Use the above link then scroll down to find the various categories of free software.

   Adaware http://www.snapfiles.com/get/adaware.html or Ad-Aware

AdAware is a privacy tool, that scans your memory, registry, hard, removable and optical drives for known data-mining, aggressive advertising, and tracking components. It then lists the results and offers to remove or quarantine the components.

CCleaner http://www.piriform.com/ccleaner

CCleaner is a freeware system optimization and privacy tool. It removes unused files from your system - allowing Windows to run faster and freeing up valuable hard disk space. It also cleans traces of your online activities such as your Internet history. But the best part is that it's fast (normally taking less than a second to run) and contains NO Spyware or Adware!

Dropbox http://www.dropbox.com

Dropbox is a service which allows you to store files online and retrieve them from any other computer.  It also allows you to sync two or more computers if you load the program on those computers.  Fast and easy.  Drag files to your Dropbox and they are instantly available to anyone who you have given access to your account or to you from any computer that has an internet connection.  You get up to 2GB of for FREE storage on their website, more if you want to pay for it.

SpyBot http://www.snapfiles.com/get/spybot.html or Spybot Search & Destroy

Spybot - Search and Destroy is an adware and spyware detection and removal tool. This includes removal of certain advertising components, that may gather statistics as well as detection of various keylogging and other spy utilities. In addition, it also securely removes PC and Internet usage tracks, including browser history, temporary pages, cookies (with option to keep selected) and more.

SyncBack http://www.2brightsparks.com/download-syncback.html

SyncBack is a flexible, and quite powerful backup and synchronization program that allows to to maintain backup copies of your files and folder, or to synchronize them, so that both locations always have a complete copy (e.g Laptop/PC). It offers different types of actions that let you choose how older and newer files are processed, which files should be excluded (by mask) and more. It offers standard file comparison based on the date and size, as well as optional MD5 checksum, which will detect even the slightest modifications to files. SyncBack also supports scheduled projects, FTP and zip compression of backups, as well as network login, simulation runs and more.An excellent piece of freeware that allows you to synchronize files, directories or drives on the same computer or multiple computers. Also has a stand-alone, non-installed version good for flash drives.

Belarc Advisor http://belarc.com/free_download.html

The Belarc Advisor builds a detailed profile of your installed software and hardware, missing Microsoft hotfixes, anti-virus status, CIS (Center for Internet Security) benchmarks, and displays the results in your Web browser. All of your PC profile information is kept private on your PC and is not sent to any web server.  This is a great program that tells you what is inside the "box", including all your software and keys,

SIW http://siw-portable.en.softonic.com/?gclid=CMnIpLb87qwCFUvCtgod2nshKw

SIW is a system information tool, that gathers detailed information about your system properties and settings. It includes detailed specs for CPU, Network, TCP/IP, Memory, Hardware, Users, Network Shares, and more, as well as real-time monitors for CPU, Memory and network traffic. SIW also displays currently active network connections, installed codecs, connected MS SQL and Oracle database servers (if any) and more. A standalone tool that does not require installation.  A good alternative or substitute for Belarc.

Free Commander http://www.freecommander.com/

freeCommander is an easy-to-use alternative to the standard windows file manager. The program helps you with daily work in Windows. Here you can find all the necessary functions to manage your data stock. You can take freeCommander anywhere - just copy the installation directory on a CD, USB-Stick or even a floppy disk - and you can even work with this program on a foreign computer.  Dual-pane capability is great.  This is a excellent program that really does work better that Windows Explorer.  I paid $50 for a program similar to this with less functionality.

Skype - Use your computer to call anyone in the world for free http://www.skype.com

Skype is a little piece of software that lets you make free calls to anyone else on Skype, anywhere in the world. Also, until the end of the year you can also make free calls to landlines and mobiles in the US/> and Canada/>/> from Skype. And even though the calls are free, they are really excellent quality. If you and your friends, family or business contacts are using webcams, you can also make free video calls. You can even call landlines and mobile phones at really cheap per minute rates.

Just like instant messengers, you can also use Skype to chat and not just with one other person at a time, but with up to 100 people in a group chat. If its a really nice group chat, you can bookmark it and find it later, which is handy for persistent chats with family or business contacts.

Other Great Stuff
Check out this site to see lots of really good open source and free software for Windows and Mac.
http://opensourcewindows.org/

Open Source software to replace that expensive stuff:

For free antivirus software here are some good sources:

Free firewall

 Other free anti-spyware programs:

 Microsoft's Internet Explorer is rife with security holes. Over the years, many of these security problems have been patched through Windows updates. But new ones continue to appear. I recommend that you switch to the Firefox browser. It's free. I think it is inherently safer.
Firefox Web Browser