It's nearly always nice to get something for nothing and computer users have buckets of free programs and utilities to choose from. The recommended retail cost of Adobe's CS3 which includes Acrobat, Flash, Dreamweaver, Photoshop and Illustrator is around $1,800.They are great programs but many people can't justify spending that amount of money on software - even of they've got that amount burning a hole in their pocket anyway.
I know there are plenty of ways of getting hold of expensive commercial, copyrighted, programs for free but a lot of people do not want to criminalize themselves or wait forever for some large program to download only to find it does weird things to their computer that a real copy wouldn't, or have to hunt around looking for cracks to get it to work properly then block internet access to it so it doesn't "phone home" for updates or whatever.
There is also plenty of "try before you buy" software around. Some is very good but has annoying "nag" screens that exhort you to buy the full product, some either has features, or even the entire program, that stop working after a set period of time. Other "try before you buy" software put annoying watermarks over the output. These are fine if you use the program is one that you need or use a lot. Other "free" software is advert supported which I find very annoying. Other free software depends on your honesty to either buy it or at least donate a reasonable amount to the authors. There is other free software that really is free, that is software in the public domain or has one of the GPL (General Public License) or "copyleft" licenses. See the Wikipedia and the GNU sites for more information.
Other free software is offered by authors as a cut-down version of their full software. If an author does this then I've only listed it if the free part does exactly what it is supposed to. You won't find software here that, for example, tells you your computer has a virus but won't remove it until you buy the full version.
Be aware that when searching for free software many sites will say "free download" which is technically true but what you are really downloading is commercial software that needs to be activated (ie paid for) before it is usable.
There are subtle differences between "open-source" and "free" software, I'll leave that for others to debate, but for most end users, well, me anyway, the end result is the same - you do not have to pay for the software. Generally speaking, all open-source software is free but not all free software is open source. Just as "Photoshopping"" for some people now means using any old image editor then "open-source" is often used to describe free software whether it really is open-source or not.
If the software author asks for a donation and you find the software useful then please consider paying what you think the software is worth to you. This is not an exhaustive list of free Windows software but those that I use and find most useful.
This list is what I use, you may find other software better suited to you and what you do.
D = asks for a donation; O = open source; C = cut down but still fully usable version of commercial software
CD / DVD Utilities
File Sharing and Collaboration
7-Zip - opens a variety of archived files (O)
Stickies - sticky notes for your computer
Skype - Video calling (C)
VLC - Plays practically anything and everything (O)
Avast - A good, strong anti-virus program
Repair & Recovery
Ccleaner - Great at getting rid of all those junk
files that PCs accumulate. The registry cleaner is fast and safe. (D)
Screen Video Capture
Expression Encoder - An
advanced audio/video-encoding and live-broadcasting application. A huge program but the video capture is great. Captures to WMV
format. The free version can only do 10 minutes captures.
Aida32 - Produces full reports on your computer
hardware. Great if you need to find specific drivers to make it work properly.
Blender - 3D graphics and animation
Web Browser Addons
Apache Web Server (O)
GIF Animator - simple program to create animations from GIF files. No longer available.
Format Factory - Able to convert most media formats but not to web formats, so I use other converters now.
LightScribe Simple Labeler. The entire LightScribe site disappeared in September 2014.
LightScribe Template Labeler. The entire LightScribe site disappeared in September 2014.
Microsoft Security Essentials - Not so good now as is was when it was first introduced.
Orbit - Download and save streaming audio and video. I found this software could not keep up with changing methods used by some sites like YouTube.
Super - A good video converter. Can manage lots of audio / video formats. I started having problems with some of the encodings I did with this software.
Surething 4 SE. The entire LightScribe site disappeared in September 2014.
Types - You know those programs that keep changing your file associations? Well, this little program lets you quickly and easily change them back. I cannot find this program anywhere now.
See what other people say is their favourite free software...